good bottom end is first priority: good bearings, solid clutch, no electrical necessary. I'll buy a complete engine if thats what you got, but i already have a good top end to use so this isnt mandatory. if you do have a top end id want it to be a "fast" one (A, i believe?)
would love a 505D but i wont hold my breath.
Could also use a 14mm bing.
so.... what have you?