I used to use PS cs3 but switch to cs4 because i was lagging when painting at high magnification. My comp spec is above their recommended requirements, not really sure why it's lagging.
If you're going to play new games at high setting, you wont be able to run at 1920x1200 resolution(especially fps games). A 22inch monitor is a an ideal. The price from 22inch to 24inch is alot for just 2inches.