Hmm, well if convertible is an important part of the itch, I've got nothing for you. Get another Miata. Or an S2000.... they are a better car in every way, just less mustachian.
Curing body roll on a miata is a piece of cake.
FWIW, my 94 SW2 was 99% as fun as the Miata to drive on the street (different story on the track), and 500% as practical. Also, it cost me 1/2 as much (built for around $2K). Still kicking myself for selling it.