I'd pretty much say you're safe to assume that the Cabrio lights are the same non cabrio models. However, I'd speak to the AUDI parts department and ask them if they are the same to be on the safe side.
Man, I'd stay away from lights like that. Why not just go with used stock Xenons? They'll look better (although that's subjective) and they'll most certainly work better. Or is it the LEDs that you want?