Go wif the ATI X800 if you got the cash
As for the monitor, go for a 17-in CRT. CRT's are inheritely better suited for gaming and are cheaper. And since you only have $1k to spend, you'll prolly have to go with one anyway. For less than $200, you can get yourself a nice monitor, like the Viewsonic G75F
. You might want to look around to see what you like, but in my opinion, Viewsonic makes some of the best CRTs around.
As for speakers, I would personally get a pair of good headphones from Sennheiser like the highly rated Sennheiser HD 515
. They go for $150, which is a bit pricey, but they are truly the best out there. I personally feel that headphones deliver much more accurate results than any speaker system for games. I only use headphones to play games [namely CS], nothing else.
If you insist
on having speakers, then you should get the Logitech Z-5500's
. Problem is, the cost about $300. If you can't afford it, then you can go for a 2.1 system like the Klipsch Promedias