From what I have read, the Nitto 555R sucks :(
and it is the only 20" option, so it forces all of us that want to hook up to go for an 18" tire. then we have the trouble of finding an 18" rim that would fit over the SS caliper.
I hopefully have this problem solved on monday, the tire is easy
Drag Radial -
MT ET Street Radial 2
305/45/R18
The rim is the hard part, very few options, and most of them custom and expensive. I'll let you know what i find though