My Pontiac Fiero was nothing short of nipplerific for AC, would absolutely freeze you in 100F weather (and it had a sunroof with no inside cover). I've been in MR2s that are exactly the same. I think the large volume manufacturers that have a lot of experience with HVAC have no trouble building in the correct size evaporators, condensers, compressors, and properly insulate all of the tubing. My Lotus Esprit - no chance, wouldn't cool for squat.
Go for the LARGEST condensor that will fit in the space available, Both compressor and evaporator should be sized to work together. Given the relatively small amount of cubic feet to cool, small sedan components work well. Better (more efficient) should a larger condenser be used. Let's not forget proper insulation of the refrigerant tubing either. IMO..