Thanks guys, I'm trying the UUC black mounts first I think. They were just $30 shipped from UUC. If they turn out to be too hard I'll try the M3 mounts instead, but great to know they'll all fit.
Dackel, too funny - I checked on the CSL mounts earlier
turns out they're the same part number as the regular M3. I like the way you think, haha.