i've seen an EF XR with 18" azzuro's and an EL GLi with the same rims, both were on superlows.
you should be fine as most are still 8" wide like 17's and will fit under the rear without hassle, front may need to be rolled out.
i have no problems with mine, however i had to have the lip on the guards rolled flat. Not sure exactly how low mine is but you can click on link in sig. to see some pics. i think its as low if not lower than super lows
i was left with the choice of getting some nice rims the other week, 17" or 18", 18" were great he said for looks, but u would feel all the bumps and chip your teeth of you had it fully low, so i chose 17", abd a drop of 2", good enough, drives great, but it's an EA, i saw a EF with the same wheels the other day, it didn't suit, I complain too much
You will definetly need to roll the guards if you want 8 inch wide wheels on the front, i run 235's on 7.5 wide rims and they still scrape the inside of the guard and mine are rolled, I am on superlows as well