Well i have 19" in mine and i think i can put 20" without problems. Here in PR, some Millenia's have 20" and looks great. I have mine with 2" drop in the front and stock suspension in rear and dont need to cut.
If u want 19", go for it, u need to use 19x8 rims with 215/35 R19 tires
If i has time tomorrow, i take some pics with my cellphone and post it here.