Firstly I have to add my 2 cents with regards to the folks at Automation Correct. My feeling is that they will be there to support their product even if they are not selling new ones. You are not talking about people that don't care.
Also all of the stove companies started as one or two guys in a garage... so just understand you are dealing with an industry that is small time (ie I think there are less than 5,000 units sold per year for all manufacturers combined). Harman was just bought out by a large national company, so they are the riskiest right now in my opinion. The best bet is to find a company that takes a personal interest in your happiness, for that you can't beat the folks at Leisure Line and Automation Correct (the makers of the Coal-Trol).
I have owned all the different brands of coal stoker stoves out there, although I have never bought a new one. I can say from personal experience that the Harman Magnum is a great stove, it is very well built and works very well. As far as the price new, I do not feel a Harman is worth the money, Leisure Line is the best value and best customer service as far as I can see for a new stove. If you are thinking of becoming a Reading Dealer I would check out all the other options as well. Alaska, Keystoker, and Leisure Line are all good companies. Out of those I would pick Leisure Line because of the Coal-Trol coming standard. I believe that within the next couple of years all the stove manufacturers with the exception of Harman will have the Coal-Trol as at least an option. Especially since the auto ignite feature is just a year or so off for full rate production.
As stated a used Harman is a good bet, just make sure you get the stove with the "pent-roof" design, the older flat roof style builds up fly ash like crazy.
Best of luck with your search, PM me if you would like some additional insights, I seem to have been collecting all sizes and shapes of stoker stoves and have experience with quite a few.