I have 17x8.5 SSR Competition (Type C) rims. Currently have 255/40-17 Pirelli Corsa PZero DOT R-compounds on them, which have lasted 5 track days and about 10 autocrosses and have at least a couple of autocrosses left in them. Waiting to go on the rims are 255/40-17 Toyo RA-1s. Anyway my SSRs are +30mm offset, if I had to do it over again I'd get +35 or +40 to move the wheels a bit further "in"; the reason is that the 255-wide tires barely clear the rear fender lips. Though a +40 offset might require modest front spacers (to allow the wheels to clear the Brembos)--which might require longer front lug studs (I currently get about 9 turns of the lug nuts).
Anyway long story short, 275s will require some rolling of the rear fenders. As for the front, you'll want to get coilovers with 8" or shorter springs to give you clearance on the inside. A bit of fender rolling and you'll be able to fit 285s all around with the right combination of offsets and spacers.