I usually buy the 1 1/2gal kit of Quik Fair. It's cheaper by volume.
As to the wire brush. A really tough one is a wire rope style.
It doesn't roll over and flex to much and can dig really good.
http://www.harborfreight.com/cpi/cta...emnumber=91281
Quik Fair:
http://store.hamiltonmarine.com/sear...term=Quik+Fair