Q: Upgrading my Graphics for MTW 2, etc

[Shieldmaiden]

Ok, I'm not 100% certain this is the place to ask, but its kind of TW related...

I recently purchased a PC and I'm NOT happy with its gaming potential due to the crap GFX card (I can't return it, despite complaining "multipurpose PC for media and games" my ass).

Anyway, I'd appreciate some advice on improving this PC, I'm thinking of replacing the PCI-E XFX GeForce 7300 LE (LE is the bit they didn't mention on the specs, bah) in it with a better GeForce - for RTW and MTW2 in particular.

A few questions then, if nobody minds.

1) Could anybody recommend a good model/brand of PCI-E GeForce? I'd be looking about UK £100 max, it doesn't have to be top-of-the-line, just a worthwhile investment for games.

2) Will I need to buy a cooling system seperately or do most cards have adequate cooling built in? And how much difference with physical size and power consumption does there tend to be..?

3) Is it possible to find out how beefy my PC's Power Unit is without opening it and invalidating my warranty? (I'd like to be very certain about things 1st).

Thanks for your time!

Oops, current PC:

XFX GeForce 7300 LE 256Mb, Intel Core 2 Duo E6300, Foxconn 946 7MA Series M/B, 1024Mb DDR Ram, Realtek HD Audio, Windows XP Home Edition