Why do you avoid overclocking?
Why are you buying an after market cooler if you're not overclocking?
A 650w Corsair would tie you over for a two card setup.
Also a 650w Antec Earthwatts which is only $70 would work too.
Get the 2000Mhz RAM if decide to overclock, otherwise get RAM rated for the board.
Get an ATI 5870 or 5970.
Why go Nvidia dude?
ATI wins all the benchmarks right now.
The only reason I see to go Nvidia is if you really like PhysX, and even then there's ways to get a dedicated PhysX card and use an ATI card as a primary.
You do NOT need a full size tower, but if you insist on having a case that's the size of a small filing cabinet, then by all means.
( I recommend Lian Li cases for your price range usually. )
As far as monitors go... at 22" LG used to have a nice monitor at 22" with 1680x1050 resolution that had 176/170 viewing angles a .27 pixel pitch.
That would have been my suggestion, but it up and disappeared.
I think AOC has a good 22", I'll check.
Newegg.com - AOC 2236vw Glossy Black 22" 5ms Widescreen LCD Monitor 60000:1 - LCD Monitors
Yep, that's the one.
I think that's my current suggestion, for a high quality 22" monitor that doesn't cost $350+
If you're willing to spend a lot on the monitor though, there are S-IPS and S-PVA 22" monitors.