i tried researching it a lil bit just now cuz i'm curious. seems like other ppl have gotten away with stretchin 225's on 19x9's. maxxed out though on 9"
225 on a 9 isn't a problem at all. Its a decent stretch but nothing crazy. With a 33et you will have poke in the front but shouldn't have issues in the rear.
I'll do 215, if you go lower.
Mine is 18x9 et30 and rolled front fender
Also, you'll be 3mm less poke than mine DSC_2560 by herbert6368, on Flickr DSC_2582 by herbert6368, on Flickr