In my area I can buy coned cross ties and rent the wedge locks that go with them and with some 3/4 ply, 2x4 bracing, and 2x4 whalers build any form that I wished. I did about a 1/2 dozen foundations this way when i got tired of waiting on form setters. Later on i found that i could make a nice set of forms with some 1/2 inch osb a bunch of 2x4 and fha straps and left over banding strap from the lumber loads. Renting forms works too but be sure to have all the right parts and whatever the face of that form looks like that's what your wall will look like. I don't know of any websites but here are a few things i found out about being a part time form setter. The pressure on the bottom of the form is about 10x greater than at the top of the form on a 4 ft wall, 20x on an 8 ft. form. Blowouts almost always occur at the bottom of the form or in the corners. Blowouts are extremly difficult to fix especially when there are 2 or 3 trucks of mud waiting and the drivers want to go home. Generally when you think it will hold, triple that and maybe it will. You don't need to oil new plywood for one pour and if you plan to use the plywood for something else it is better not to have oil all over it. (learned that one the hard way). And i'll say do your homework if you want this wall to look nice and you have never poured a wall before. You don't get to fix anything the next day. Hope that helps a little. RT. My specialty for a couple of years was one sided forms for retaining walls on property lines where no overdig was allowed. RT