Adjustable height tow ball mount

More of a product review, but figured I'd post it here since this relates specifically to towing.
I tow a few different trailers, with three different sized tow balls. One trailer is about 30' long and low to the ground, so I needed an adjustable height hitch with decent capacity. After searching around a bit I found this, and bought it from Amazon for about half the price that Curt sells it for. Like it a lot, easy to adjust. I'm trying to see if I can get a spare or additional ball mount platform for it, so I can keep different sized balls on each mount. With the adjustable slide in place with a locking hitch pin, it's secured and you can put on/take off the ball mount in seconds. Standard locking pins though won't fit through the adjustable height brackets to lock the ball mount in place though. With the ball mount off when not in use, it also doesn't stick out as far as the previous tow bar slide I had there, as shown in the picture.
It's max capacity is 500#'s shy of the V6 tow package capacity, but it was the best adjustable height tow mount with the highest tow capacity for a reasonable price. There are others that have higher capacities, but the price and size went up considerably.
http://www.curtmfg.com/part/45901