There is another alternative...
If we gather a number (probably 5) of like-minded Miata pilots, there's no reason we can't run a regional class with Houston's STC rules (or rules of our own making). I suppose we could even go for a "run what ya brung" Miata class.
I'm willing to support such a venture, but my primary goal over the next 12 months or so is to make my ride "feel" like I want it to and improve my driving.