Ok so I just bought some pegs and they only fit on the front tires? Where do I get pegs that will forsure fit my back tire?

I will assume that the pegs do not fit the back because of a larger axle diameter.
Measure it, and then order the right size. any reputable BMX shop should have some that fit (Danscomp too)

^^ that sounds right. Also make sure there isn't an adapter inside.

got those oversize axles for hard abuse?

This is very important. If you don't have the oversized axels they will snap, it's happened to me once and I learned my lesson very quick.