Wheel size and offset for 2003 GTS

My son has a 2003 GTS and for a high school graduation present I agreed to buy him a set of wheels for the car. He picked out an ADR M-Sport in Hyper-Black as his choice but he wants to put 235/40/18 tires on 8.5" rims. They have a 35mm offset which I think is negative. Anybody know if these will fit his Eclipse with no problems. He is dead set on the 8.5 inch rim as the design is slightly different than the 7.5" with a bit wider rim lip.

He also has a '95 GS that he has modified substantially so he is fairly knowledable about Eclipses and assures me these wheels will work but I am skeptical.

I have seen lots of info that says a 225/18 tire on 7.5" rims will work fine and some of the folks he has talked to say the 8.5" rims will work "but it will be close". What is close?

Anybody know if these will fit his car?