I am interested in the same thing.
I would like to upgrade wheels, and I do not do a ton of track days, but nothing would suck more than having a wheel explode on track or an autox event.
My primary reason for wanting another wheel is that I am thinking of BBK, and need the clearance if I do so. Having raced motorcycles (road, SM and MX) I am pretty hard on brakes. BUT, have yet to track a car.
Assuming that I arrive at Brembos (I'm leaning towards the RS kit), I will need to either space the snowflakes out 5 to 10mm, or have wheels w enough offset to clear the new brakes. I prefer to not run spacers if I do not have to, but like the strength of the stock wheels. So am looking for ideas from those that have tracked cars extensively...