gbeef:
the rails are miter slot and T-bar combo rails from peachtree woodworking, I got a 4 foot set for about $30. the gear and rack was another $50 or so from mcmaster carr.
something to think about: My sliding panels slide in the same track on both sides, so they are limited in how far out they can go. My middle panel is about 12" max. it is possible to go wider than 12", but it gets complicated. the tracks for each wing will have to interlock, I.e. you need four tracks rather than two so you can get more extension. I am not explaining this well. My setup is like a regular drawer system where part of the box is still in the cabinet. you would need a full extension drawer system to get the sides out further, if you follow. I will see if I can make a quick sketch and post it to clarify this.
Are you a Michael Park/wrc fan (screen name and driving cab - possible connection?) Big WRC and F1 fan here.