Yeah, that's the problem. I have a similar problem, but it's is due to my card (ATI Radeon 9550).
I dunno about places, by I can recommend some stats.
Try and get a computer with the following:
Intel Centrino Dual Core CPU
nVidia 8 series and above GPU. Try and get an SLi-enabled GPU (which is basically two GPUs stuck together, for better and more consistent performance)
1-2 GB DDR2 memory (RAM)
Vista Home Premium/Ultimate
Alienware specialize in gaming desktops and notebooks. I highly recommend them.