I think Cat woman would sell well, but Penguin? Not really. He doesn't have much going for him. At least Catwoman is cool looking, plus they can make a BD version with the Selina head and crazy hair.
Penguin is just too ugly and perhaps the least popular villain from the 90's/90's Batman films. I think more people would buy an Arnold Mr Freeze, just for the lightup features.
A dirty little guy with a basketball for a body and little to no articulation, yeah, not selling.
But...but you just mentioned the selling points.