what size will fit????

I just ordered some saleen replicas, I actually found them in 10.5" rears! so I am going from 17x8's, and going to 18x9's and 18x10.5's. My question is what size tire will fit on the rears, and not rub on anything. I like the profile of a 285 35 tire on a 10" wheel, but with the extra 1/2 " what size do I need?
I would like to keep my Flowmaster tail pipes, and quad shocks, but I don't require them. I felt behind my friends 96 cobra rear tires, and it doesn't leave much room, with the 285's. I don't know about removeing the quad shocks, will that cause a problem? If any of you 96-98 guys are running H&R SS springs, that is what I have to work with. There are some pics on my cardomain link below of the clearence I have. Please help guys!!!!! Thanks chris

bummer deal once again!!!!!!!!!!! I had to just go with the tens, seems that someone happened to steal the last pair that was availiable in 10.5's. B.S.!!!!!!!!!!!!oh well now to see what will fit with the 10's. I really am interested to see what I will have to use on the front.
http://members.cardomain.com/chrisbudl1
As you can see from one of the pics, I have already trimmed out some inner fender, to keep stock tires from rubbing! Help guys ?