[Henry Schmidt]

Depending on your proposed course of action (IE: design of your 3.2SS) the small port SC cylinder heads offer the greater number of options. Valves are the same size and angle so no advantage either way.
The main difference is the intake flange. The SC flange is taller. This allows you to get more creative with your porting. Basically, the 3.2 head is already over-ported.
The taller SC flange also allows for space to machine an injector port if you choose to go old school with MFI.
The only real benefit to Carrera heads is the head temp mounting point. If you end up needing that feature a good machine shop can add it.