I was going to say all that Don already said...
To add to those ideas here is a link to the unistrut and trolley stuff.
http://www.eberliron.com/store/category/Unistrut_Trolley_Assemblies/1056.htmlI think this would be better than barn door hardware in this case, and more compact.
For the hoist I'd want manual control for carefully positioning things, not electric or air.
Something along the lines of a 1/4 ton chain hoist would be about right. Might find one with a loop of chain to operate it.
http://www.harborfreight.com/1-4-quarter-ton-lever-chain-hoist-67144.htmlGrigg