I was asked about where some of the equipment shown can be found. In addition to the traditional photography retailers listed below, a manufacturer that makes some specialized macro photography gear is Kirk Enterprises. Their focusing rail comes with an Arca Swiss adapter already attached, which probably doubles the cost of the focusing rail, but as anyone with Arca Swiss or Really Right Stuff plates know, their stuff isn’t cheap.
Kirk Enterprises focus rail with Arca Swiss Adapter $269
Really Right Stuff focus rail with RRS Adapter $345
Rest assured you can find generic focusing rails w/o quick release adapters for anywhere from $60 on up. Manfrotto make a very good one that I use for about $89.
Also on a local level, if you want to try out a macro lens before you jump in and buy one, West Photo in Minneapolis rents the Canon 100mm Macro for $20 a day, the Nikon 60mm Micro for $15 a day, and the Nikon 105mm Micro for $20 a day. The also rent a set of extension tubes for $10 a day.
Traditional Photo Retailers – local and mail order (with macro photography being a specialized niche the local retailers may not stock a lot of macro equipment and may have to order it in.)