Justins17c43

Hey guys, to start off please don't ask me to search the forums, I've been looking for 2 days and cant seem to find a straight answer for this lol. 17 c43 cabriolet, currently stock suspension with the option 19''s, 12mm spacers in the front and 15mm's in the back. Cracked my wheel and i don't like these anyway so I want to upgrade to 20x8.5 in the front and 20x10 in the rear. Running these with 35 offset for the front and 50 for the rear i should be fine with 235/35s for the front and 275/30s for the rear. Question is, if I lower it with H&R non-adjustable's will this setup still work? I drive the car hard at high speed so I don't want any kind of rubbing. I'd like it to look flush but it doesn't have to be ridiculous. Can someone give me a hand with this? Also suggestions of where to purchase wheels would be appreciated as well. Thanks in advance!