Just completed the CadPlan 501 model last fall. Super! I hadn't done any welding in many years, yet the finished product can handle stacking 1500# hay bales to the 2nd level on a trailer. I recommend CadPlans. Purchased the hyd. cyl. from Northern Tools, and the controls from MetKit.
Equipment required: loved the little mig welder for tacking, but the stick welder is a must for the heavy welds. By the time you are finished you'll know a lot more about running a bead. Used both 6011 and 7014. Need the metal cutting band saw, drill press, ½" drill (and bits) and at least 1 hand held grinder. I had both a 4½" & a 7" and both had their place.
MetKit can send you every thing you need all cut out. But to save a little money, and really feel like it is your project find a metal supplier that will work with you. A lot of them will help you out just because they think you are nuts!
If I were doing it over, I'd use standard 7/8" pins that you can buy at a farm supply instead of trying to make the 1" pins as proposed. Turned out to be a real pain.
Good Luck!