All Zenit and Pentax lenses will be OK.
Some of them are getting quite expensive these days... re-discovered to be useful again.
For example, I found Zenit Tair-11A (135mm F2.8, stepped down to f3.5 - f4) to be excellent for AP - VERY sharp in the centre (with a bit of coma at corners and no AC whatsoever).
You can find a lot of info on compatibility here:
http://www.bobatkins.com/photography...focus_EOS.html
http://lewiscollard.com/lenses/m42-dslr-compatibility/
https://en.wikipedia.org/wiki/Flange_focal_distance