whether or not you go with a staggered setup front and rear its up to you. I would go with 19x8.5 front and 19x9.5 rear
In regard to tires, I would go with 235/35/19 front and a 275/30/19 rear. Alot of people have gone with 245/35 front but I don't like the fact that it is taller than the rear tire. Not by much but it still is.
I think that a 225 tire on an 8.5 in rim is going to be a bit small and it will look kinda stretched. its also going to be larger than your stock wheel/tire combo.
If you want to go with the same setup all around you could go with the 19x8.5 and run the 245/35 tire. It will be roughly the same size as the oem but will work just fine.
I don't know about your offset choices but your front could be as low as probably +35 and still be safe. The rear would have to be about a +44ish or more to give you the ability to not have to roll your fenders.
http://www.rims-n-tires.com/info_specs.jsp
use that link to play with different tire sizes to find what will work for you