I am using an OCZ Goliath2 with 80mm TT SmartFan2 on my XP2500.
At 192x11 (2118Mhz or thereabouts), I get a reading of 47C under Prime95 load.
On the DFI KT400A, I have an unlocked Palomino XP2000, with an SK-7 + TT SmartFan2, and it runs @ 1.90Ghz at about 47C (paly always hot even when not clocked lol).
Any heatsink you put on it should work, as most aftermarkets are better than the stock ones that come with retail cpus. I highly suggest checking out SVC.com and seeing if they have any SK-7 left for $15.99.
The SLK's are awesome, as is the Aero7+ if you like a lot of noise, Zalmann makes nice ones, and of course, I love my OCZ Goliath2. They Goliath3 is only $20 with a 60mm fan (I have to use a 60mm-80mm adapter, but its uv-green so it looks great heh.)