There are lots of options out there when selecting wheels. Personally, I have Vossen's on my Lexus and love them. If you are looking for 20's you should first decide if you want a staggered fitment or not. If you want a staggered fitment then I would recommend 20x9 in the front and 20x10.5 in the rear. Tire wise, if you are not lowered, you have several options. If you are lowered than you are looking at 245/30/20 rubber if you want to minimize rubbing, for the front. In the rear it will depend on if you are lowered or not but a 275/30/20 or 285/25/20 should work just fine. As for the "flush" look you want, I would recommend buying the right offsets for your car and then using spacers to create the look you want. I would do this for two reasons, 1) you live in MN (I Live in WI) where the land of crappy roads exist and 2) it gives you the option to "tuck" or flush.
I can help you narrow down your options if you like, just need a little more info.