Small Form Factor Asus P5Q-EM motherboard, which graphic card?

Hey guys,

i'm planning a gaming htpc, and i've just spotted the P5Q-EM µATX board, which should be perfect for that. However,i've heard that seperate graphics cards won't work well with it? Is this true? Would it be able to handle the new cards like a GTX280 or 4870x2?

Another question: the case i'm planning on using isn't that spacious. I was thinking of watercooling it, however i think the maximum i can go is a dual 120mm radiator. I'd like to watercool the cpu/gpu/northbridge/southbridge and maybe the RAM with it. Would this be possible? I'm not going to overclock anything.(well, perhaps a little so i can use 1066mhz ram)Regarding the small radiator size: would you guys recommend a quad core cpu?

Thanks!