the 323, 328 coupes have less aftermarket and are less desirable than the 325,330 motors which are a generation newer.
Ci always means couple and not converible which would be called either iC or maybe even CiC.
I don’t know why anybody would prefer the earlier motor with money not factored in.
back to the original point… they’re great cars, but expect to spend money to maintain them… they got a lot more shit to go wrong than you mustang does, and more will go wrong… it’s not a bad thing, just understand and budget for it.
also, don’t buy it as a sports car, you’d be better off starting with an M3 for that duty.