Thanks for the replies.
ZiG: Yeah, there is that option or
http://www.northracecars.com/Discpixinstall.html for 4bolt. There are two problems with either setup. The first being that those calipers/rotors are quite large. I could try redrilling the bracket and rotating it, but even then I think they are just too large to fit w/o hitting shocks/panhard/frame. Second, I am redrilled to 4x100 to match the Miata fronts. Also I really don't want this axle getting any heavier than it already is.
TRX: Thanks. I think I'd like something with more pad options.
I've found that the newer Miatas have calipers where the ebrake is aimed correctly. I'll see if I can make them work. I also may change rotors (arg!) and have to start fresh.
Cheers.