The main medical justification for whole body is to preserve the parts of the nervous system (and any other information-encoding tissues) that are not in the brain, for any additional fidelity that may add when reconstructing the personality. Transplantable organs might not be valued for this purpose as highly as the gut and spinal column, so there is room for a spectrum of preferences here.
Simultaneously signing up for organ donation and cryonics versus only cryonics. Does having less organs decrease the likelihood of cryonics (including revival) working? Is it a good idea to have only your head frozen anyway, to save on electricity and storage? Do the benefits of organ donation outweigh any costs it could possibly incur, since organ donation is known to work?
Discuss.
I'm an organ donor because signing up was quick and easy. I'm not signing up for cryonics, because I anticipate that my family and close friends will have a harder time overcoming their grief if my body is not actually present at the funeral.