The NB HSF is pretty easy to remove. Pull out the spring clips and twist. Scrape off that pink gummy stuff and read the code on it. Then lap, use Arctic Alumina or another ceramic-based paste, and maybe 2 tiny drops of superglue, and put the hetsink back on. I slapped a 50mm fan on the top with just a dab of silicone.
The SB, likewise can use an old video card HSF because there are holes from the spring clips.
I used some cheapo radio shack aluminum heatsinks (about the right size for video card ram (old kind, not BGA) on the mosfets, then siliconed a couple of thick 40mm fans on top of the rows of transistors.
For all this, my best stick of ram still tops out at 198 FSB with aggressive timings, no matter what board its in....