I'd suggest the E1505 with the ATI Radeon x1400 card... that's what I have and it's extremely powerful for daily use, and doesn't lack in the gaming department. I ran Painkiller on near max settings until I got bored doing the same thing over and over on the demo, and I haven't had any problems running CSS, and I game almost daily. I run medium settings on everything just to keep the performance up, but I've never really tried it on max... the game looks amazing as it is on medium.
Also... I have the T7200 processor in mine, I'm not sure that that's available in the 1505's anymore and I don't know why. If you're going to be gaming, I'd recommend getting the EAX software with it and a good pair of headphones. When you use stereo widening... eq... all of that stuff, on CSS I can hear guys coming quite a ways before they actually get there =).