As of the time of writing this question, the two major providers of cryopreservation in the US are Alcor, with 181 patients and 1,317 members, and the Cryonics Institute, with 177 patients and 1,859 members.
These organisations might differ in the chance of reviving their patients if the initial quality of cryopreservations is higher in one or the other, or if one organisation is likely to last longer than the other, or if when revival becomes possible one is better able to arrange this than the other.