The second gen, Z4-based M-coupes (E86) were offered from '06-'08. They still offered the S54 engine that was introduced for the E46 M3 and fitted to the Z3-based M's (E36/8) near the end of the production run ('01 MY and possible briefly '02). IIRC, the hp was slightly lower in the E36/8 (315hp) due to differences in the exhaust over the E46 M3 and the E86 M-Coupe (333hp).
The E85/86 M-roadsters and coupes didn't seem to sell as well as their earlier counterparts. IMO, they have more of a sleeper look and subdude interior. However, for a tall guy like myself, they were much more inviting. Also, the E86 coupes had more of a fast-back look versus the shooting brake style of the earlier cars.
Last fall I sold an '06 M-roadster... always preferred the styling of the coupe to the roadster but the roadster was a winner for my wife and I due to our geographical location and climate
. I have little to complain about the car other than it being somewhat difficult to live with as a daily driver mainly due to size and some extent stiffness. Fuel economy wasn't great but that's not why you buy one of these. It was a blast to thrash around corners. Didn't really get too many tire kickers wanting to talk about it but that is probably due to its similarity to the regular Z4. Apart from hood chines, quad exhaust and big wheels, it was quiet.
Hope this helps some on the newer cars. Coupes are certainly more rare that the roadsters but they are out there and really are quite reasonably priced I think. Look hard and you maybe just maybe can find one still covered under a CPO warranty. My '06 just expired this past November.