X2 leadteck 8800 gtx cards water cool them or not?

i have two leadtek 8800 gtx cards with koolance voodoo waterblocks. im not going to overclock them. so do i really need them water cooled? games i play are crysis, modern warfare, world at war, need for speed. i have a quad cor extreme at 2.66 i want to water cool. i have an apogee gtz bock for that. 2x2gig dominators. i have an old koolance exos 2 system. i want to OC the chip. thinking of getting an mcp655 or 655-b. also have a danger den extreme ice II 2 fan rad not installed. others were telling me to ditch exos 2 system. what are soem thoughts here. if more info is needed i can supply.

say i put the stock fans back on the 8800's , performance will be no different correct. how would temps look when i play games on high settings? all i want to OC is the processor.