Try Speedway Motors and Lebaron-Bonney.

I have a pair of Speeways stainless chopped 2" 32 posts and they're very nice.

LB makes nice stuff as well.
They have a top kit that's easy to install at home.

I think they have side curtains, but perhaps not for a chopped top car.

Look for Brianangus' ongoing post here on CHR about building his own top irons and the like.