The Ronin widebody kit is about a +85mm front + 80mm rear, however you have to be careful about just doing math at the apex because in back our minimum clearnace is at about 10 and 2 o'clock on the fender lip. I can say that 315s fit easily in back, 335s require careful offset selection and some trimming but work fine as well.
I always recommned customers run a tire section 20-30 mm wider than the published rim specs. Typically that means we recommend 10.5s with a 285 or 295 section up front and 11s or 11.5s on 315 rears. I run 295s all around just to simplify my life. If you're into a 335s we'd recommend a 12" rear rim if you want to shoot for a nice squared off sidewall.
You might conisder going 18s instead of 17s. Tire selection is quite a bit better. Overall tire diameters are shorter which is very helpful up front as fore/aft considerations come into play. Last I heard, Josh18s2k (sp?) was running a reverse stagger with 18s up front and 17s in the back that worked very well for him.
CCW's are the go to guys for multi piece wheels and the used pricing is barely more than new so I'd just get what you want. SSR Type F wheels can be had in an 18x11 one piece. RPF1s are about the best bang for the buck going, but on the downside they've been done to death. Weds tc105n are the lightests, only cost a hair more than the Enkei's and require the least spacer (that's what I run). Those 4 wheels were the only one's I investigated significantly. If you don't care about weight, Mustang FR500 knock offs are my all time favorite cheap wheel for FCs.
FWIW we do have an FC widebody in stock so no waiting if you decide to go that way. You can order the full kit or the rears alone. If you pull the trigger I'll give you full specs and recommendations on wheel sizing.
-Joel
PS my widebody built up starts here:
http://www.norotors.com/index.php?topic=1274.msg23779#msg23779. The car that originally inspired my quest to find the tri-points was this one...
He's also running a Ronin hood (back when it was Ati-Hardt).
He could have done a better job at optimizing the gaps around his headlights and he did cut open the topside vent, but every time I see shots of this car it just makes me say "damn!!!!!!!!!".
