I've been searching every where and can't find any tires wider than 225 in 15" Does anyone kow of anywhere I can get some.

 

There's nothing in any kind of decent performance rubber, or in the right sizes for an RX-7. Unless you want something like a BFG Radial T/A or a race tire then you're basically SOL. There's the Hankook RS-2 that's now available in a 225/45/15, which should be good for a 1st gen, but it's the only street tire in that size AFIK, anything else 225 in a 15 is a 50 series.