This is what I did with my 370z today.
20x8.5 front 20x10 rear +25 offset (I think)
Hankook V12s 245/30/20 Front 275/35/20
I really wanted to go wider in the front but they don't make a 20x9 or 9.5. I'm hoping these look good and will ride well.
The think I'm concerned with is being able to drop on swift springs once I have these on.
They get installed tomorrow.. Pics coming!