I would suggest 6 max - game selection across the board is going to be much better over the next 5 yrs than playing full ring - and 6 max accentuates the better player's advantages and avoids set-miners and other nits, those playing a viable short-stack stategy and bots..

Some very friendly advice.

Your hrs/week for THAT many tables is overly optimistic. You'll likely burn out very quickly.

You can resize tables on stars, so you only need two 21" monitors.

Pro poker SUCKS as a career. It's a GREAT job...but a crap career. This is moreso if all you're shooting for is 50k/yr. It's a LOT of stress and awkward hours (if you want the best hours) and a social strain. The novelty of being a poker player wears off fast. Pro poker + relationships = very difficult.

Get PT NOW.

6max will undoubtably be more fruitful as ex suggested.