33"s should clear fine with 2" lift, but you may also want to read our tech article on JK lift and tire size, it should answer some of your questions and give other useful info:

How much lift is needed for larger tires on my 2007-up Jeep Wrangler?

 

I had the same issue as you....my '17 sport came with the dinky 225/75/16 tires.
I sourced a set of 17" factory wheels from a friend and upsized to 285/70/17 tires with 1.5" wheel spacers, they'll fit but you cant flex much without getting into the fenders.
I ended up lifting it 2" (using JKU springs on my JK) and changing over to flat fenders.
After calibrating for the new size with a Flashcal F5 I'm averaging 17-17.5mpg......It's not a speed demon by any means, but I don't have any issues with merging onto traffic or holding 75mph on the highway.