Can of worms, open!
The one thing I will offer is tires seem to be so personal in terms of people's driving style and preference, both from a brand and model, but also in terms of ideal pressures and how they feel as a result. Good example: I love Toyo RR's, I know Troy and Will (and others) don't really like them at all. Hoosiers are supposed to not love a significant slip angle, they reward very smooth driving. I now have at least some experience - ~20 HC's with my R7's, and that has been my observation too. If I drive them back to back with my RR's, which seem to like a little more slip angle, it messes me up a little until I get back to the Hoo-Hoo's. I corded one of my RR's at Thompson (after ~18-19 heat cycles - and they were great right up to the cord, in fact the other 3 tires still have significant rubber on them), so I am going to mount up some Nitto NT01's I have as my first day morning practice tire. They seem to be pretty close to the RR's in terms of longevity and performance, the RR's are probably a smidge faster, but I know Scott R, for example, loves the NT-01's and he is damn fast on them.
The other wild card tire that at least 4 or 5 people in the club are trying out is the new Maxxis Victra RC-1 which I understand is reasonably priced and it looks like they have your size. Maybe some of those folks could chime in and make your project even harder!
Obligatory anti-anti-Miata statement, since it is you, Stephan. Yet another reason why "miata is always the right answer" is 205/50/15 tires are cheap and plentiful! The spec miata Hoosier SM7 (same as the R6, is $179)