Got my whole kit for $25 at southwest wheel, but any trailer store should set you up for close to the same price.
I know getting started fabbing can be a little overwhelming , but you have to start somewhere. But be careful it can be very addictive...
http://www.southwestwheel.com/store/...xle-seats.aspx
http://www.southwestwheel.com/store/...bolt-kits.aspx