New to the 2005 forums...need rim advice!!!

Hey guys, I usually hang out in the 5.0 forums, but my wife and I have added another pony to the garage. We have recently purchased a 2005 sonic blue gt. I am now looking at some new rims for the car.

I am interested in knowing the correct backspacing that I need for the car. If anyone can help me out, I'd appreciate it. :nice:

Here is the link of the wheels I like.

http://cgi.ebay.com/ebaymotors/20-G35-350Z-MUSTANG-SC430-20X9-5-STAGGERED-WHEELS-RIMS_W0QQcmdZViewItemQQcategoryZ43960QQitemZ8062013799QQrdZ1