water's the best , but can be sort of a pain .
1 always go with 3/8's hose min. size I.D. , 1/2 inch is ok but it can take up alot of room .(a mix of sizes seams to work best as for it allows the water enough time to cool )
2 dont mix more then 15% coolant or 20% water wetter... ALWAYS use distilled water !!! (you have been warned)
3 keep air flow thru case with at least a fan for the HD's and a fan cooling the Ram, and video card if not on water too.
optional water secrets , run a seperate 12 volt transformer for your water .( in my case it runs the radiator fans also)
run a Magnetic impeller type pump .