More info please... what type of R compound are we talking here? Do you want to run Hoosiers or RA1's? The RA1's have more heat cycles in them at the expense of ultimate grip. I don't think you'll find a much longer lasting sticky than the RA1.
Now, there are plenty of SM guys running a full season (10-12 events) on two sets of RA1's (and a few who do it on one
). So say you get two practice sessions, a warm up, and a race per event. That would make roughly 4 cycles per event. Multiply by number of events.
As for sticky street tires, I can't tell you what you'll see for wear, but I can tell you that heat cycles aren't an issue. I wouldn't be too worried about the sun either unless you lived in AZ or the deserts in CA. Honestly, I've never known anyone who's thrown out a street tire b/c it wasn't sticky -- it's always b/c its worn out. If I were to drive my car at its normal pace, I wouldn't get a year out of my street tires (and I put about 6,000 mi on the car this year). But that's not b/c they are "heat cycled" out but b/c the shoulders look like hell and they're generally getting low on tread.