I've made my own just like the kits that are sold my many companies, but its long hard hot work. There is alot of steel bending involved. You could probably get a local welding/fabricating shop to do it for you, but I did them myself. I used 1/4 inch cold rolled steel for the hinge arms and 1/8" inch for the pivot housing and 1/2" steel tubing and roller bearings for a smooth action. I have also made a set from aluminum to lighten up the load. Both worked well and were way less exspensive than the stuff they sell. I just replicated a set with a few added conviniences.