Get whole life insurance. You want to insure against the possibility that, say, next year you will get sick, not die, not be able to work, but face very high prices for extra life insurance because of your illness. Also, dangers of relying on saving enough money so in 20 years you can pay for cryonics out of pocket include having a spouse making claims on the savings, legally needing to spend the money on health care expenditures (if, say, you are in a nursing home), losing the money in a lawsuit, or having the government tax away much of the savings.

I have whole life for cryonics + term life to provide for my young son for whom my death would be much worse financially if it happens before he becomes an adult + disability insurance. I'm an economist.