Cryonics organizations typically offer two options: whole-body preservation and neuropreservation, in which only the head or brain is preserved.
The neuro option is grounded in the idea that everything that defines you is in the brain, and that any future technology able to revive a brain would also be able to provide or regrow a body. It also allows resources to be focused on preserving the brain to the highest possible quality.
Whole-body preservation appeals to those who prefer to keep the entire body intact, and avoids some difficult questions about future embodiment. There is no single right answer; it is a personal decision shaped by your beliefs and budget. See what cryonics costs for the financial side.