It depends how much you want to pay! I also tried making one according to plans and it was a disaster!
I've got a few places but they are quite expensive (premier etc) but I seem to remember there is a shop on eBay that sells decent equipment fairly cheaply.
We've got an ADW, I think it may have been from Adams Agility, though not sure if they make them! It's one side a dog walk and the other side an A frame, and then if you take it apart the dog walk part turns into a seesaw, its a great way of having 1 piece of equipment to train all contacts!