I wonder if EFM private labeled the stoker from Combustioneer? The Combustioneer units were designed for bituminous coal only, and EFM would be the opposite. But, EFM could have purchased the Combustioneer unit to get a wider product availability.
Combustioneer discontinued the furnaces, boilers, and the S20 stoker. The S30 is the smallest they manufacture now. The S30 is also very similar to GregL's Iron Fireman unit, which was a bituminous burning stoker. However, Greg didn't have a lot of luck burning bitumninous in it and modified it to successfully burn anthracite instead, which is the subject of an older thread around here somewhere.
I have a post over in the Bituminous section with a some information on what's available from Combustioneer and a boiler that works well with the S30 stoker unit. It's a bit of a monster, but it ought to make a nice setup for someone (like me) that has access to cheap bituminous.