I, & several others, are running the TR Motorsport C4 which are 17x8 et40, with 245/40/17.
I'm running them on Dinan springs and no rubbing but there is not a lot of extra room.
I think 255 would be a problem. I do wish the TR motorsports were a little wider (The Kosei wheels are also 17x8), but the tires I'm running (Bridgestone Potenza RE-71R) are spec to 8-9.5 rims.
This combination has been fantastic on the track for me.
Keep us posted as to what you decide upon and give us info on fit & track performance.
https://www.tirerack.com/wheels/Whee...5&autoModClar=
https://www.tirerack.com/wheels/Whee...=Sport+Package