2003 Eclipse GST Wheel Size & Offset

My son has a 2003 Mitsubishi Eclipse GST and he wants to add a set of custom wheels (which I agreed to buy as a high school graduation present). He has chosen an M-Sport wheel by ADR but he wants an 18" X 8.5" wheel with 235 X 40 tires. The rims come with a 35 mm offset. The car presently has 17 inch rims. I have checked and there will be no issues with speedometer calibration as the original tires and this combo are the same circumference and diameter but I have concerns with the offset and the overall size. Anyone know if this combination of 235 X 40 X 18 on an 8.5 inch rim with 35 mm offset will work on a 2003 Eclipse GST? I am trying to persuade him to go with the 225X18 on a 7.5 inch rim which several web sites say will fit with no problems but he wants the extra size for looks.

Also, the packages come with Falken Ziex ZE-512 all season W speed rated radials. I've never owned Falken tires. Are they at least average in wear and traction. Any comments on them. They are an upgrade from a tire I have never heard of (Hankook?).

you mean GTS?

I definitely think that package would rub on the outside due to its low offset.