For the monitor, you really need to go look at those in person. The one your eyes like is the one you buy. You can still get it online if it's a better price. Most folks these days go with 23" LED. ASUS is very popular in monitor's also although I prefer Samsung.
Yeah the one powerful card over two smaller cards is great advice. Maybe consider the 7970 and sacrifice a little off some other component. That Hyper 212 EVO is a good cheap cooler, everyones mentioning it.
One word of caution on the 7000 series cards. If you still play any older DX9 games, the new cards seem to have a bit of performance trouble. this may or may not be fixed with future BIOS and driver upgrades.
I am very much about backward compatibility for games. I still play Neverwinter Nights 1, Baldur's Gate, Diablo 1, Starcraft 1 and a lot of old games. I don't mind if these games don't have really high performance, but I would like them to be run decently. Do you know what I should expect? I was mad when I couldn't install Red alert on XP LOLZ!