If you _can_ try to get an MC68060RC50 with the E41J Mask.
Also try and get the fastest SIMMS you can get (50ns or better).
These coupled with a Cyberstorm 060 or Blizzard/Apollo 060 will allow for overclocking of at _least_ 66MHz
Switch to 1 wait state on the RAM and you'll get 80MHz easily. (This probably results in worse performance?)
The E41J mask will run cold enough for desktops