Will these wheels be fine on the 09 v6 coupe?

Try it and will find out.

I wouldnt buy wheels just to "try"

Rear yes. They will fit your front but they will poke out of the fender. You will definitely need to roll your fenders if you drop it, that's if it clears. It should though I guess. I don't know how much 8 offset does because my wheels are 8.5 +38 front. I guess you should try ;)

I'm still on stock suspension... I don't think wheels poking out the fenders will look too nice... Are your wheels flush?

Btw, tires are 245/40/18

check out this website. It calculates what you are asking. It will give you a reference based on your current wheel
http://www.1010tires.com/WheelOffsetCalculator.asp