If you don't like the idea of permanent (or semi-permanent) bonding, you can always do it the stone age way:
Get some garden wire. TIE the HSF to the GPU (don't forget the thermal goop) thru the four holes beside the GPU. Slack? No problem. Get a old, short pencil or two and stuff it in the loop behind the card to make the tie tout. Worked for me on my GF2MX for a couple of weeks till I found out the stupid thermal paste I 'borrowed' from my university lab was water based and had evaporated! (started having visual oddities due to heat problem but otherwise the unit was fine). Took it off again and reapplied the proper type of thermal paste and worked fine for a month till I swapped off that GF2MX for a supposedly 'more overclockable' one (which is the lousy, frickin' GAINWARD I'm stuck with today). This way, I was able to use old Pentium HSFs without spending $$$ for all those BLOrbs and Lasagna nonsense.