Oh no, no, no on the HTR Z, I don't care how cheap they are... The Michelin Pilot Super Sport is not the absolute best tire for what you are doing, but it's easily top 10 in the 140 and higher Treadwear class. It is an extremely consistent tire. The ONLY other tires you should consider are: Nitto NT-01, Toyo R888, Dunlop Z1/Z2, Falken RT615K, Hankook RS3, and BFG Rival. I would rank your SuperSports 7th or 8th behind those for outright performance/hot dry lap times. Slightly behind those tires and your SuperSports would be the Yokohama Ad08, Kumho Ecsta XS, and maybe the Bridgestone RE11. That's it! Don't consider any other 140 + up Treadwear tires for the type of tracking you are doing!

Oh and I agree completely that different tires need different pressures!