I picked up a 48x66" piece of aluminum deck plate for about $170 at the local steel supply, had it bend a couple of times at the local industrial sheet metal shop for $25, and used the kubota mounts that I already had for the canopy. It would be darn easy to build the mounts; just a couple of 1/8 or 3/16 sheet metal triangles and two 30" pieces of square tubing. Look at a canopy at the dealership and you can copy the plan in about 5 minutes. No welding involved. It will save you about $300...
My neck doesn't bend very well anymore, so I mounted a camera on the canopy above the 3 pt hitch, and put a small monitor up front. Now I just back up to the implement, and have the arms within about a quarter inch of where they need to be. I'm still able to muscle the final alignment pretty easily.
A lot of the guys here use and like the quick hitch on the back. Radio Shack has one pretty inexpensive. Your implements have to have the same width and height of the 3 point mount... For the stuff I have, I'd agree with your dealer.