Wheel Offsets???

Anybody know what the 2007 Prius Touring model's 16" wheel offsets are??

I just bought the car today and want to put even lighter wheels on the car for
better acceleration, handling, steering, braking, and gas mileage.
The touring models stock 16" weigh 17.2 pounds as I weighed them.

Anybody got pics of there aftermarket wheels on their Prius?
Looking to keep the same 16" size, but would consider 17" wheels.

So far I like these:

http://www.enkei.com/RacingSeriesSpecs/RS+M.html

Suggestions?
Thoughts?