Palmer’s How to Brew outlined “batch sparging”—also the “no sparge” method—which made it clear to me that all I really need is the mash tun, no complications needed. Batch sparging is simple: you mash the grains with the hot water, drain off the hot wort, pour a second “batch” of hot water into the grains, and drain that off. Done. No need for a second tank setup and sparge arm assembly!
I already have a 30-quart pot that I boil my full batches of beer in, so really, the only thing I needed was the mash/lauter tun. The other bit of resistance I had was in acquiring/converting a cooler into one—and quite frankly, this resistance melted away once I saw how easy it truly is to build your own.
With photos! In case you’re looking to put your own system together. Yes, it’s really that easy.