Hello Hunta... welcome to the forum.. I would look into a refurbished EFM boiler with the oil burner option. There is an EFM rebuilder right near you who has been selling rebuilt boilers for several decades.. I'll find his name and post it.. I would also PM member 'coal berner' he has the phone number for the EFM rebuilder..
I'm not fond of oil burners attached to coal boilers.. they seem to be a compromise.. by far the most popular method is leaving the old [if servicable] oil boiler in place, and adding the coal boiler in series.. the single chimney can be handled.. But since you want to go with a single unit,, I think I'd prefer the EFM. Especially since the EFM can have as big a coal hopper/storage bin as you can make.. it is only limited by your space.
Member gaw has a keystoker in your area, coal berner is installing an EFM, so you have several knowledgable boiler users in your area.
The EFM rebuilder's forum name is scrapper_23jr