I'm not extremely well versed in appropriate rotor thickness for street vs. strip use. The ones he is looking at and the ones I plan to use are .81". What size do you like to see for the street?
.81 should be fine for street use, just not the thin .35 for drag racing.....I found this out when I was going to run the Strange front disc brakes. They are for racing only.
Look on Ebay, there are tons of rear brake conversions, that are for street use, with heavier rotors.