Does this 17"/18"setup seem like it will work?

I don't like a 225 tire on a 8" rim. They always look too skinny to me. But that's just an opinion.

Nice thing about a 245/45-17 on the front and a 275/40-18 in the rear is they match a C5 Vette for tire size. Makes them a size that should be readily available for a long time, and relatively cheap to boot.

For what it's worth, I am running a 245/45R17 on the front of my Duster, but I have about 5mm more positive offset than you are talking about. Amounts to 3/16" of an inch. I rub the bolt in the rear of the wheel opening once in a while but could fix that with less caster or a button head bolts. So height wise it should work for you as well.

72bluNblu (last time I checked) runs a 275/35R18 on a rim with 35mm positive offset. That rim put's tire about an 1" further out than yours would, so even allowing for differences in brakes and such, you should be fine there.

The other issue in the front is the tie rod end. I am close on mine so with 5mm less offset you will probably be fine there.