Probably get different answers from everyone but I had 19x8's with 245 rubber on my old vs ute without a drama. They only ever sometimes scrubbed a little on the inside when going over steep driveways at an angle etc. Mine was pretty low too. This is it to give you an idea...
Hope that helps,
Cheers
I have 18x8.5's with 235's on and mine dont scrub at all, even when loaded with 500-600 kilos in the tray, and mine's lowered too, depends on the offset of the rim...
9's are probably doable, but the max in my experience. I'd be trying one on there before you buy a set of wheels. As above, the offset will be critical. Probably a little easier with 235's aswell. Also make sure all your rear rubbers like upper and lower control arms, panhard rod etc are all in top condition to reduce the amount of sideways slop in the rear end.