I have one of these:
http://www.harborfreight.com/motorcycle ... 60810.html
mounted to the optional stand. I probably wouldn't buy one again. The pain is that it really needs mounted to the floor if using the easy-mount bar. I put some mollies in my garage floor, but I typically don't want to take the time to put the changer in place for just one tire. A large garage would negate that issue. What really works is the tire changing bar that came with the car tire base on which it fits. Note that the big, u-shaped frame that holds the top of the axle bar is probably not needed.
http://www.harborfreight.com/portable-t ... 69686.html
http://www.harborfreight.com/media/cata ... _23500.jpg
The PitPosse item looks ok but you are using tire irons:
http://pitposse.com/tirechanger.html
I would make my own; a franken-changer combo of both. And in fact I have one mounted on my trailer. (Of course last weekend I didn't take the parts or an extra tire and needed them. Doh!)
Mount a rod (or rod holder) vertically on some object that isn't going to move very easily. Like a trailer (I'm usually changing tires near the trailer, either at home or out in CO or UT. I mounted a pipe against the side rail and the axle rod slips into this. Flat surface to hold rim steady preferred.
Use a rod (threaded or smooth) that will fit through the axle hole on your rims. The rod needs to extend a foot or so above the rim. If threaded, then get a spin on nut like in the PitPosse model.
Put rim onto rod. You need to keep the rim from turning, but that can be accomplished with another rod through the spokes, a lightly tightened u-clamp, or a strap around some spokes and the trailer rail.
Use that HF tire changing bar to unmount / mount the tires. It hooks under the bead, then uses the mounting rod as a fulcrum. You simply rotate the bar around and it removes the bead. Lot of leverage. I imagine a similar bar is available by itself.
Does any of this make sense? I don't have a picture and really don't feel like taking a wheel off ...
Another idea I remember seeing at a moto shop years ago: a 20 or 30 gallon metal barrel, with a vertical rod mounted like on the HF moto changer, and the barrel filled with concrete. Rubber tubing on top lip of the barrel to protect the rims & spokes, heavy enough it didn't move.
In other words, make something like this:
[youtube]
http://www.youtube.com/watch?v=WtOUa2jNYvw[/youtube]