In the "quasi-DIY power generation space", take a look at Lister engines & their clones (Listeroids)[0]. You end up with a surprisingly efficient[1] engine when you run diesel that drives any belt system you want: flip from a generator to a mill to a water pump. They can run on most any alternative fuel you want to use - biodiesel, waste oils - and their simple low RPM construction means they are durable and easy to work on.