Love my 140, I'm heating 3000' I have the dual stoker 140 with paddles, I only use the 2nd stoker when it's real cold, -20's and then it is only for a week or so. I recommend the paddle also if you plan to burn coal only. I also believe there is not a dual stoker auger fed only the paddle feed is dual. But I could be wrong about that. I used 4 ton of rice this year, I keep my house at 68 and I am ducted into house system, There are quite a few 140 owners on here and I haven't read too many bad things about them or any stove on here..
Over $4000 sounds a bit pricey
, I bought mine 3 years ago, for $3000,
Good luck on your search there are alot of good brands out there and doing your reseach is the correct way to start.