No that won't do. You need someone else to prepare the body: you know... rigorous workouts for strength and physique. Ideally the person is an excellent cage fighter and has the reflexes of a top-tier video gamer.

The practice of illegal clone brain transplants figures in some of the Vorkosigan series books: The clone-children of various customers are raised in cohorts, and taught little while enduring years of strictly controlled diets, cosmetic surgeries, and exercise regimes.

Then, one day, the are told their important and distant "parents" are finally arriving to bring them away to their new life...

Anyway, the point is that any aging wealthy pedicidal murderers are also gonna insist the body is perfect before they move in, meaning some other brain is going to be doing the work.

Thanks for bringing that up, it's probably time got for me to reread the Vorkosigan Saga.

And you also reminded me of the flawed but moving film "Never Let Me Go" from 2010 about a more present version of this. Oh, and there's also Michael Bay's "The Island".