Years ago when I shot smallbore I bought a relatively inexpensive camera tripod and went from there. Add 8"x4"x1" block of wood and some foam and you're good to go. A drill press can make a neat pattern of holes in the wood for cartridges/pellets.
Neal Johnson's and Champions Choice both sell the most common aluminum types that you see on the range. Champion Shooters Supply sells the rod style (similar to the spotting scope stands), and ESP also makes/sells them, but he doesn't have a website.