Shop Elevator?

Part of the "deal" on getting my 60 x 40 shop was that mama got a 20 x 20 exercise room. So... I went with 16 ft eaves and built a second floor over the space. I went with 8" C purlins on 24" centers braced in the middle with 25/32 floor plywood with the dovetail. I'm not planning on putting engine blocks up there but will be storing some bulky stuff like tires and wheels etc. My "elevator" platform will be about 7' x 4' framed from 2 x 3" square tubing and lifted by a 1500 LB A/C winch through two snatch blocks bolted to the side frames. It will "roll" in two 8" red C channels on each side with two 8" hard rubber casters with upgraded sealed bearings mounted on grade 8 5/8 bolts. Any of you guys make anything similar? I will post pics once I get started. The elevator will be on the wall to the left in this shot.