but my first call would be eBay, since both AMS and fallsoffslowly list their stuff on there. I think bartons put some of their stock on their as well.
In the garage:
Kawasaki ZXR400 L3 - shiny
Suzuki DR800 - bouncy
1978 Suzuki GS400 - PROJECT RETRO RACER!
Kawasaki GPz500S - for sale soon
Honda CG125 BR-J - in bits