I used the 200mm one too (http://www.ebay.com/itm/Fotomate-200...-/300794593182). Make sure that the one you are getting has a tripod socket in the center - that way you can flip the rail and put the front standard on the "slider" and still be able to mount it on a tripod. The rail has the second tripod socket on the slider/bottom thingy and with one of the two screws provided you can lock the standard in place. Probably the easiest rack-and-pinion focus system ever.
The rail has a groove, so if you make the mounting plate for the back round, you can also have back swing. Tilt and shift for the back is a tad bit more complicated to make but still very doable. If you want more pictures of my beast and how I made it, let me know.