Been looking at Central Georgia Generator on ebay. 1800 rpm 4 pole
ST-10 KW New Style Brush Generator Head 120-240V | eBay
I guess it's time to come out of the closet...
My MEP-002A is my second diesel engine. My first is an Indian clone of a Lister 6/1 stationary diesel.
The ST series gen heads are very popular for people setting up homebrew generators for all the usual reasons. They're a standardized, dirt-simple four-pole rotating field design that has been used in China for the last 30 years or so to provide electricity wherever it is needed, commonly driven by one of the Changfa hopper-cooled diesels. They use a z winding to provide field current, so voltage regulation is done with a one-time rheostat setting. Not high technology, but extremely serviceable. If you take one apart and sort it out you'll have a very durable machine with a total spares kit of a rectifier or two, two bearings, and some brushes.
STs come in a wide variety of build quality from utter crap to not-too-bad. The guy at Central Georgia Generator has received universally positive remarks on listerengine.com and microcogen.info both on the quality of his products and his willingness to stand behind them. His prices are slightly higher than you can get some ST gen heads for, but the quality is always better than the cheaper heads - I would definitely regard it as a win to get one from him instead of somewhere else.
See also the pages at utterpower.com about the ST gen head for more detail about what you'd be getting.
No, I am not a customer, have never met the guy, and have no relationship fiduciary or otherwise with him.
That said, if you can get the mil-spec MEP gen head for your engine, I'd go that route. It's a really nice design, and it mates up to the engine with no adaption needed. If you're handy with wiring you don't really need the control box - it's overly complex because of the need to manage changing output modes on the gen head. Unless you're planning switching from two leg 240 to three-phase 208 you're just not going to need stuff like wide range voltage control and the output interconnection switch.
Again, though, the box ("control cubicle" in the TM) is a convenient all-in-one control solution if one is available cheap.
