I am welding one this week, that will hold what you are looking for, but alas the brewtroller, valves, and other parts are to be added later. We (me and 5 other guys all brew together) are building slowly in phases. We have keggles, now the stand, then the pumps, then the rims tube or herms coil, then controller, then automated valves for both liquid and gas.
It will have 3 2' by 2' sections for vessals, with 6" between sections and supports to hold keggles lower than the surface so that larger vessels will rest on the main supports. With storage underneath for the keggles when not in use.
So basic dimensions will be 2' wide by 7' long and 2.5' tall + caster height. Made from 1.5" square 14 gauge steel tube, the keggle supports will be 1" angle iron. Caster will be determined later.
I am in Dallas and will probably be welding it on Nov. 9th. If you want, you could PM me and come by and see what we are doing.