Wheel Fitment Help Please

Hey guys, at the risk of being redundant, i was hoping to get some clarification on wheel .fitments/sizes. I would like to get the Vossen CV3's(20x9 +38 and 20x10.5 +45) and lower the car either on Teins or Eibach springs. The tire sizes im looking at are 245/30/20 and 275/30/20. Other than rolling my rear fenders, is there anything else i need to worry about to make them fit? I've seen people running those wheels on here, so i know it can be done, but of course gotta drop the ride to make them look right. Not trying to roll on rubber bands either...as the roads in charlotte suck...thanks the for the help in advance!

If this is going to be too much of a hassle i figure i'll try to find some 20x9/20x10 istead.