You could run 18x10" ET25 with 275/35/18's and 18x10.5" ET27 with 295/35/18's, but there is only one tire available in that combo, that's usable, and that's the nitto NT-05.
To make a recommendation, I'd need to know if you're considering r-compounds or street tires, and if these are dedicated wheels or dual duty.
Eddie. have the 18x10 and 18x10.5. will have gc camber plates. will be trying to run r888s. either 275/35 and 295/30 or 285/30 & 295/30. they should be the same as nt05, should fit, no?