I'd definitely reccomend the 255s, but used the 245s should be easier to get. When goin used, you take what u can get.
Here's a pic of my 225s on a 14x6.

If I can pull that off you can definitely rock 255s on an 8. Especially since that's +3 compared to my 14s.
My swap is definitely closer to done. I just sold my LS7 heads and picked up a 404 ci L76, complete engine. I'm redesigning my dbw throttle linkage, and may have a line on a nismo LSD. It's still a snails pace though. At least my miata keeps me driving competetively in the mean time. I just met a guy who bought a stock 1.6L miata for $500, and slapped on some falken 615s (they are only $63 ea in miata sizes) and is having fun at the autocross. My wheels cost more than his entire car+new tires! I really admire the guys that get out on track and go fast. It's crazy how much difference seat time makes.