You might be happy with an 850, but DO NOT BUY A V70 or anything newer.
Why? Because you are a competent mechanic. The Volvos from 1998 on are designed to keep you from being able to work on them. Virtually everything except things like brakes and belt changes require that you diagnose the problem using a $50,000 computer that is ONLY available to Volvo dealers. In order to properly service the car, you will have to drive to your distant Volvo dealer, pay him to read the fault codes, then take the car back and fix it yourself.

As someone who does nearly all repairs myself, I find this incredibly frustrating, and I promise you, you will too. If you are someone who does not do his own work, the fact that the only Volvo dealer is nowhere near you will also be a big problem.

The biggest lesson that I learned in buying my 1999 Volvo was to research service-related things in advance. (Like: can you buy a factory shop manual for a reasonable price? Volvo doesn't even print them for models after 1998. Can you buy a tool on the open market that will tell you what the fault codes are? Not for a Volvo. What are the common electronic or expensive failure items, and how much do they cost? (Tough info to get, since service departments will probably tell you their cars are great until you own one.)