How will 17s with a 39mm offset look on a G sport?

"smallish" as far as diameter. The offset depends on the width as well.

ya i need a winter setup..i'm over in the east coast now

Yes, those will work on your car on any 17" wheel ranging from 7-9" wide.
-GP-

i am having the same question for my 07 sports sedan. Not really concerned about whether it would look too small or not. rather whether the wheel with 39mm offset will fit over the caliper.... called discount tire and tire rack. both said anything from +5mm and up will work, which seems contracdictory to a lot of posts here.... so confused... please help. thanks.

as for clearing calipers, it also depends ALOT on spoke design of the rim...

since stock offsets are in the +40 range, +39 should fit...