Which fan or should I go with water cooling?

hi...

my build will be...:

core i7 920 cpu @2.66
asus p6t v2 deluxe mobo
powercolor hd 4870 x2 graphics card
probably x-fi elite pro sound card with hub
silverstone element series 850 w psu
antec skeleton 'case'
500 GB sata 2 HDD
ram is prob 6GB kit (2GBx3), Ballistix Tracer 240-pin DIMM (with LEDs), DDR3 PC3-12800 memory module
BL3KIT25664TG1608

what I would like to know is which fan would fit the case as it has a huge 250 mm fan at the top...the best hsf coolers are just too big to fit...or should I go for an alc domino water cooler...also I haven't thought about cooling the graphics card...I have an oem hsf which came with the cpu but I'm not sure but think it will interfere with the 250 mm fan on top of the case so I prob need a side mounted fan for hsf...also the pc will be used tfor gaming...and I don't know the first thing about overclocking so prob wont be overclocking anytime soon...
thanx for feedback in advance...

Liquid cooling isn't necessary with the 920 if you don't OC. Here's the heat specs

TDP: 130w
Thermal Specification: 67.9°C

You might try a scythe mugen 2. Place the included fan blowing through the heatsink and add a second fan, opposite, blowing outwards. This should keep your I7 below 32°, depending on the case temps(which since it's open air should be low). And that's if it actually fits.