water cooling the power regulator's isn't necessary, but then again WC'ing isn't necessary. everything runs perfectly fine on straight air cooling.
however, on my board, even with a fan over the PWM area and a WC block on the mosfets, the chokes get EXTREMELY hot... like 150Â°F hot. of course i'm dumping alot of voltage to the CPU and more to the NB and HTT link, so that's making them hotter.
i personally just like the look of no fans and all WC'ing blocks and hoses. as well as cooler temperatures on everything that generates a good deal of heat. i also have three 360 rads to cool everything, so that helps.
for the mosfets, get a koolance MVR-40 with a 107.5mm heat plate from the koolance website or another place like performance-pcs.com might have them in stock. the heat plate is just a tad too long and they don't make any that are slightly smaller, so you'll have to either file off an end of the heat plate or slightly open up the mounting hole in the mobo that is closest to the PCI-E slots. i did the latter.
i'm also running an MCW-30 on the NB and SB. the only thing i don't like about the swifty's is that they have the nylon top that isn't ideal for screwing in short thread metal barbs. i was unfortunate enough to strip part of the threads out
if you want to use metal barbs (since there are more options for metal barbs, like swivel fittings), get a koolance CHC-122 for both NB and SB. if you have the stock air cooling on a dual-slot video card in the 1st PCI-E 16x slot, then you'll need a CHC-125 for the SB. it has offset holes and angled fittings that allow the hose to sneak out from under the GFX card.
oh and before you knock koolance, look at their newest stuff, like these blocks i've mentioned. they're all copper block material with a nickel finish.