Thanks fellas and props to any future M.E.s...
I went 295s all around for a couple reasons...
-It's only a hair larger than the stock diameter. Your next two step sizes in 18s are 315/30 and 335/30 both of which are significantly taller.
-295s fit well on an 18x10.5 wheel (OK it's not hella flush, sorry for letting you guys down....

)
-10.5 is the widest you can get most of the light weight one-piece stuff. The only exception I know about is the SSR Type F which goes to 18x11.0.
-Beyond that that you're into a three piece wheel. Everyone wants close to top dollar on Zilvia.net so I never saw anything that interesting and that left me shopping new...
-As a 3 pcs wheel CCWs become your next viable option. Only options are Classic or LM series because they don't have anything one piece in the right offset. (They have a few standard molds that they machine everything from.) I've seen this done too many times so I wanted to be different.
-Ability to rotate is a big bonus since tires get expense quick.
-Finally 295s are the widest you can get Advan AD08s which was really the tire I wanted to run.
For future reference my 0.02 is that 295/30 315/30 would probably be about ideal to fill up the fender wells but not push it. (18x10.5 and 18x11 SSRs?) My eyeball says a 315/30 335/30 could probably be made to work but it'd be quite a bit more work and you run the risk of the car sitting kind of high.
As it is, because the tires stick out further they also move further fore/aft when you turn lock to lock. I've had to move the factory wheel-well ducts forward about 3/4" and I'm working to make/mod fender linings because I have my accusump plumbing duck through there on the passenger side.
All the disclaimers aside, the first time I laid eyes on the 295's I had ordered I blurted out an honest to goodness "holy hell..." (<-- an inappropriate oxymoron if I've ever heard one, but still basically gets the point across).
I've save the exact wheel info for SNS. Anyone looking for a set of Volk RE30s 17x9+35s? I seem to be stacking up more tires than I need.

Left to right that's
295/30r18 Advans
255/40r17 Potenzas w/ Volks
245/45r17 Mustang (keep saying I want to try drifting
245/45r17 Mustang spares
225/45r17 RA1s on Evo wheels (also FS, cardboard so I don't jack up the powder coating but you gotta dig that flat spot

)
185/65r14 Honda (LOL)
Random spares, Roberts old 275/40r17s on the bottom that I might try drag racing with someday.