Alot of people (myself included) are making HERMS type systems in the 1-1.5 BBL size using Stainless Steel 55 gallon barrels as the vessels. Some get really fancy but ours will be a very simple system utilizing an external HERMS heater (a 10 gallon hot water heater) rather than the more typical design of putting the HERMS coil in the HLT. This will free up the HLT for more tasks as we plan on using this system for back to back brews for a 3 BBL fermentation. We made the brewstand ourselves using steel angle and we are using 32 tip Natural gas burners for the HLT and BK.
http://www.cpapc.com/32-Tip-Round-Nozzle-Jet-Burner-P470C244.aspx
Our initial build will have only the bare minimum valves and ports in the vessels, relying on old school methods such as "sticking the hose in the HLT" to get the water out. I know, shocking. The MLT will be the most exotic with a port on the bottom, a false bottom, and will be mounted to a tippy dump to get the grain out. We will also have a grant that doubles as a hop back that I plan to fabricate from an old keg involved in the system.
For pumping, we're using a three station peristaltic pump and silicone tubing. This will allow us to have up to three things pumping at once (think fly sparging), or use all three in one vessel to increase the speed of the overall transfer for the bulk transfers.
Let me know if you have any additional questions. You might also try joining the HBT group in my sig, Going Pro.