Wow this thing is getting expensive, I'm a few hundred over budget already. It doesn't help that I kinked my copper HERMS coil and had to trash it, $70 lost. Now I'm not taking any chances and went with a SS one from stainlessbrewing.com.
It was built with 26' of 1.5" square steel tube, and 42" of 1" flat bar stock. The design was to minimize welds and materials. Luckily my buddy owns a metal fabrication shop and we went from steel bar to painted up in 3 hours. The heat shield were cut on a computer controlled plasma cutter table which made life easy.
Set up with kettles and MLT, looks damn close to the design!
Burner and heat shield
Dims on Google Sketchup