Here's the hoist I recently installed in my garage. It's intended to help me load/unload the truck, work on my tools, and load bigger blanks onto my lathe. The fixed portion consists of 10' section Unistrut mounted with Unistrut brackets, all rated at over 2,000 pounds. The brackets are bolted through the drywall to doubled up 2x4's laying on top of the bottom of the roof trusses. The 2x4's span 12' and are supported by 6 trusses and a doubled up 2x6 one one end (already there for some other purpose). I used a Unistrut angle brack at each end to limit the travel of the trolley. The 4-wheel trolley is also Unistrut and rated at 750 pounds, the weakest link. The hoist is a Warn Works Pulzall, with a capacity of 1,000 pounds. I have the 120 vac model, but it aslo sells in a 24 vdc version. It features variable speed via the trigger, LED load indicator, ON/OFF switch and a forward/reverse switch. I decided on this unit to have the flexability to use it eslewhere on different applications.
My first real tryout was to lift my new 530 pound MM16 bandsaw off the floor and put it on 4x4's to install casters. The hoist lifted the BS easily and smoothly. The ceiling did not appear to deflect at all (note that the drywall cracks next to the Unistrut are from a bad mudding job and were there before I started the project).
http://home.comcast.net/~jbiddle/pics/hoist4.jpg