I intend to sign up for cryonics in the next few years

Why not sign up now? To get started, just fill out this form and Rudi Hoffman will find insurance policies for you and walk you through the rest of the process. (You have clearly put some research into this, so if you have some other path, take it, but "the next few years" is too vague of a time frame for you to ever decide "now is the time to do it".)