I used to do field support for doctors offices, really fun, anywho...
If you are expecting someone in a doctor's office to run regular backups, who is not an IT person by trade, then you are in for disappointment. You can give them that option when you build, but in 90% of the cases I would say they will not keep up with it. That is, of course, until it crashes the first time and causes all sorts of hell with which you will have to fix ( bad flashback)
There is nothing wrong with AMD if you pick a tried and true cpu/mobo combo. The main problem they are having right now is name recognition, which may hurt you when you present him with the machine. AM who? For image purposes, Intel might be better. OTOH, if he is reasonable which I am sure he is, you can explain the value AMD brings and he should be ok with it.