Looking good man!! A Miata has been on my list of things to do for a long time.....mainly because Öhlins makes coilovers for them still.
Have you checked out the two main Miata wheels (I'm sure you have)?
I have 949 Racing 6ULs 15x8 +36 made for your car. They're incredibly light and IMO look great.
Also, check out Jongbloed Series 500. It's another light, sharp looking functional wheelset made for Miatas:
Link