Ricardo...
There are tons of nice wheels out there that would go great with your triple black car. One good resource for finding these wheels and decent pricing on them is http://www.honda-tech.com/. You can often find discounted prices on gorgeous Momo, Nardi & Personal wheels, among others. While it's obviously a honda-centric board (which seems to work better and better around here as the weeks pass ), several of the vendors advertising on there also carry Miata hub adaptors. The adaptors listed previously are also great, and I've heard rave reviews about the painless one that already has wiring for the airbag stuff.
Any thoughts on maybe using a quick release for your upcoming steering wheel?