re: .243 for deer?

Although I'm not a fan of the 243 for deer hunting, this is a different situation. I agree w/ those who rec a good recoil pad and a muzzle break. As far as a specific load, I'd recommend something loaded w/ a 100 gr Nosler Partition to best assure yourself of adequate and, hopefully, an exit wound, as well.

Another thought would be to consider using a handgun such as the Thompson Center Contender or T/C Encore. W/ the latter, you could hunt w/ a 7-08 or 308 and not have to worry about your neck at all. Handgun hunting is a discipline that takes a lot of practice, but you've got time to get started if you wish.

Sorry to hear of your health problems but glad to hear you're recovering well.