So it seems from searching the consensus for an 18x9 and 18x10 would be to do:
Front - 245/40/18
Rear - 275/35/18
Problem is the fronts in the KDW2 are back ordered for at least another month with everyone I've called.

Anyone out there running a 245/35/18 front?

Using - http://www.miata.net/garage/tirecalc.html
It looks like the 35 on front and rear match up % wise closer than using a 40 front and 35 rear.

Any other tire sizes you guys would reccomend.