You cold do this... assuming you don't care for the "stanced" or "stretched" look....
265/35/20 up front running the 20x9 +32
295/30/20 in the rear running the 20x10.5 with a +22
Both of these would clear provided you rolled the rear fenders and took time to double check everything. There's always room to run more agressive offsets / setups with the understanding that the role this plays on your wheel bearings, tire life, suspension etc.
Rims and tires has a great calculator that I highly recommend if you plan on doing any type of custom setup -- staggered or not.
http://www.rimsntires.com/specs.jsp
Those tire sizes you listed would really throw off your gearing, stearing ratio, and a number of other things.
If you want the stretched look may I suggest 225/35 up front and 265/30 out back. This will keep the rotations about the same front and rear.
265/35 in the rear would be a slight stretch if you go with a 20x10.5 -5 to achieve the look / stretch accounting for the fact that you'll be rolling the fenders.
How aggressive? Are you willing to roll the fenders?
Those tire sizes you listed would really throw off your gearing, stearing ratio, and a number of other things.
If you want the stretched look may I suggest 225/35 up front and 265/30 out back. This will keep the rotations about the same front and rear. You can play with your offset from there. Use the +32 as your starting point with OEM flush fitment. If your getting coils I recommend installing the coils first, check your clearances, then pick the rims. Clearance, and setup will change once your dropped.
The 225/40 would not be considered a stretched up front. Drop down to a 20x8.5 with a +30 on OEM and you'll be able to achieve that. 265/35 in the rear would be a slight stretch if you go with a 20x10.5 -5 to achieve the look / stretch accounting for the fact that you'll be rolling the fenders.