Ask the cryonics organization that you plan to have freeze for any forms or templates they have. Having a lawyer check them over should be cheaper than having them made from scratch, and they'll probably be better, too.
My cryo provider is CI, and I've not only gotten hold of all their forms, but my lawyer has been exchanging emails with their lawyer to work out various details.
Practical General: always shop around for a lawyer. Use google to find specialists in the relevant field, the more familiar he is with what you need done the more effective (including cost-effective) he will be in doing it.
Practical Specific: this area of law is likely unsettled and whatever is worked out beyond a garden variety will is likely to not have much practical effect on your remains getting where they need to be in a timely manner. To ensure expeditious handling of your remains you probably should make sure that you maintain close connections with reliable people who are well apprised of your wishes (and that those wishes are clearly documented, this is a simple matter of creating a will that a trust and estates lawyer should be able to advise you of cheaply).
Theoretical: Does one increase one's chances of reanimation more by signing up and planning for cryonization or by allocating an equivalent amount of resources to bringing about AGI?
First, shop around. Clearly they are unfamiliar with "cryo[ge]nics" and might not be the best outfit in your circumstances. Second, maybe a template like this can lower your cost.
I'm unfamiliar with the protocol for shopping around for lawyers; the firm I'm currently dealing with has been the firm my family has been using since, well, before I can remember, and they've always treated us well.
Part of the arrangements being made are to find at least one funeral home willing to perform the immediate steps - then there's the life insurance policy (only part of which is for cryo-preservation), Estate Trustees, personal care PoA, the will itself... I freely admit that there were aspects to even ordinary wills and PoAs which I was completely unaware of before my first meeting. None of the standard do-it-yourself will packages cover anything close to what's necessary; that's why I would like professional assistance.
Asking people who should know (jimrandomh suggests your cryo organiztion) is probably the best way to find a different lawyer. His suggestion of a template has some chance of reducing the cost, especially if it comes with citations to relevant authority (which may not yet exist).
Have you considered trying to locate a Canadian cryonicist that has already had similar legal documents drafted? Perhaps the relevant cryo providers would be happy to ask around for a Canadian volunteer who already has such an agreement to discuss this with you. After all, being able to obtain this agreement is a prerequisite for you to become a customer, and so it is in the cryo provider's best interest to assist. Once the person is found, you could either ask whether you can use a copy of their agreement, or if it belongs to the lawyers, you could ask the lawyers to give you a better deal since they already drafted one of these and can make changes to the existing copy.
Also, if you choose to lead the construction of a public domain contract for this, then stating that this is your intention may draw more interested people to pool money, and would also result in making a much bigger difference to the world when you overcome this obstacle. You might also find additional resources this way like lawyers who have experience with these.
I don't know enough about law to tell you whether it's likely to be useful to consult an IP lawyer to ask whether a contract, once bought, can be placed into the public domain, but I know enough about human nature to know that if lawyers have a way to prevent their contracts from being released into the public domain, they will want to use it.
Or you could make temporary arrangements like the Alcor website recommends. They say not to delay because you might find yourself in a situation where it's too late. If you get something adequate set up now, you can improve the setup and make it ideal later.
Not to rain on your parade, but even having a complex legal framework in place is no guarantee it'll have the desired effect.
Who knows what these contracts will or won't imply decades down the line. Once you get older, you'll have to have them rechecked, which may be more expensive than was having them drafted.
There may be little substitute to having a family going through with your wishes and organizing the relevant details upon your passing, or you yourself being sufficiently powered on until shortly before your death to facilitate the immediate next steps.
I have just received a message from my lawyer, regarding the preparations of my cryo-based will, power of attorney, and related papers. The most significant quote reads as follows:
Due to the complex nature of your wishes and the undeveloped area of the law surrounding cryogenics and the transportation of a human body out of the country, your file has required and will require further extensive time and research to prepare and draft the necessary documents to ensure that your wishes are correctly stated and that they will be carried out upon your death. As such, in order to complete any further work on your behalf we will require a retainer from you in the amount of $2,500.00. Please contact our office to arrange the payment of the retainer. This can be paid by cheque, cash, credit or debit. Upon receipt of this retainer we will proceed to draft the documents in a manner that best ensures that your wishes regarding cryogenics are carried out.
This is somewhat more than I was hoping, and expecting, to pay. While I do have a line of credit which I can use to pay the immediate cost, I do not have sufficient income to pay off that cost any time soon, and I am thus debating whether or not to pay it.
One option that occurs to me is that if my law-firm is able to nail down a set of documents to maximize the odds of a Canadian cryonicist's will being properly carried out, then that would be to the benefit of a number of cryonicists, here and otherwise; perhaps even enough so that it could be in the interests of cryonicists here to help cover the legal fees, instead of having to hire new lawyers to separately re-develop the same paperwork. (It would be reasonably trivial for me to provide proof of my lawyer's existence and the retainer request.)
I'm also open to any other ideas that anyone here could suggest.