I will post this up in the lightweight wheel thread but want to answer the best I can here first.
1) Toyo RA1 will wear really well, very predictable and do not heat cycle out like some R comps do, you can get used take off from race teams a JBRACING tires.
2) No 15x8 or 15x7 will fit over an 11.75" rotor BBK I know of, just got back from test fitting wheels at Goodwin Racing, they know what they are doing, see note below. I asked about the TD 15x8 and I was told no go.
3) 16x8 Enkei RPF1, 4x100, +38mm 14.8lbs, roll formed, fit the car great and easily cleared the BBK as well as did the 16x7, I have a set I just left there with
![Smile :) :)](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
A 4x100 conversion can be done for a very reasonable cost for the DIY group, for bolt on and go, still some work, then get a more complete kit but still reasonable at around $1200 for wheels and the parts to convert.
4) If you want to run 15's it looks like just the 15x9 +35mm Konig Dial In, Konig Helix and probably 6UL will fit but it is a very serious amount of work to fit the wheels, rear camber change a must. Of course you might be able to fit custom wheels but the front and rear offsets would be different so cannot rotate them.
NOTE: There have been some one off, very custom, very deep mounted rotors on special hats and brake caliper mounts fitted under 15x8 wheels caused by building to class rules, costly and a waiting period.