well i got a Akasa with a 2600rpm 800mm system fan (came standard). Its suitable for up to 2800XP has a copper core and runs my overclocked 1700XP @ 166FSB 33*C idle and just around 43/44*C full load. It use to keep my 2100XP pally at around 46*C full load. So this HSF seems to be a good one and for £15 seems to be pretty well priced as i got it with a modded blue LED fan ..gazz
I have the Alpha PAL8045 heatsink, and it runs great. I used to have a sunon 39cfm 80mm fan that rotated @ or around 3000rpm, but recently switched to a ThermalTake Evercool fan I found laying around, which does 6000 rpms or thereabout. There's been absolutely no difference in temps.
If I were you, I'd get an SLK-900 and slap a ThermalTake SmartFan II on it. That seems to be what most people get the best OC with because of the SLK's extreme efficiency.
If you're stuck with the Alpha, don't despair. They're good, just not 'elite' anymore. Make sure and use Arctic Silver 3 (I'm using AS2 and it's still AOK) as your thermal paste and everything will be groovalicious .
Edit: Oh, I'd say any 3000+ rpm 80mm fan will work as long as you have sufficient airflow in the case. Make sure and have at least 1 intake and 1 exhaust fan. Good luck!