Greenhouse heat

ello. I'm new to the forum. I search and read the forum all the time but my first time posting.
I'm looking for help with heating 2 greenhouses. One is 1200sq ft and the other is 432sqft. I live in northern California below the snow line. I am trying to keep to a budget so I am looking to put an indoor forced air furnace in the large one and some sort of wood stove in the small one or maybe a pellet stove. I know allot off people use outdoor wood boilers but they are a little expensive. I would like one one day. I am thinking about the Englander furnace or daka for the big one. These are around 1200$.
For the small one, I am not really sure. It's a small space and it is covered with double layer poly. I'm worried it will get to hot in there and then it will be freezing come morning.
Things to add: the small one I am going to re-cover with double layer poly and will be used only in the winter. The big one will be used march - November.

I wanted to know what you guys thought about the cheap wood furnaces and which ones have the biggest firebox for the money. Also some ideas for the small greenhouse. Something to mention is that live off grid. I have a decent solar system with backup generator but power is conserved whenever possible. I live on 20 acres of oak and madrone and wood here is easy to come by.

Thank you for the reply!. I accidentally made 2 posts. Does anyone know how to delete one?
I'm thinking about the Englander 28-3500 or the daka 621 or whatever has the biggest Firebox size in that range. I am having trouble finding information about firebox size. I am trying not to wake up in the middle of the night if I can help it. I would like a furnace so I can run ducting down the greenhouse so it will heat evenly and circulate air.
I'm off grid but my solar system will have no problem with some furnace blowers.
I do know how to season wood. I heat my house with an older lopi. Hardwood like oak and madrone is really cheap to free here.

For the smaller greenhouse Its such a small area it will be hard not to overheat or be filling every couple hours. I have been thinking about getting a used non epa airtight stove (like a schrader) that I could really choke down. I know they aren't efficient. I know creosote would build up.
Maybe a cheap pellet stove.

I heat my house with wood. I have never had a wood furnace though. I have never heated a small space with wood. My only pellet stove experience was almost 20 years ago and that thing was problematic.
Maybe I do need to bite the bullet and get a wood boiler. But I don't know anything about them and it seems like it would be expensive after pex and heat exchangers but I don't really know how much they cost and there might be an affordable option.
Thanks

Thanks for your reply fred. I have seen those. They are a cool concept.
This is the boiler room. Does anyone have any suggestions for furnaces. Biggest firebox for price. They are not sold in California so I can't just go to a store and compare. I'm going to have to choose a furnace and drive out of state to get it.
Please someone.

Thank you sloeffle. It does look like a nice furnace. Drolet claims that it uses 40-50% less wood then a standard wood furnace. I know the new epa stoves are more efficient but is it really that much? I don't have much experience with new stoves. I have an old lopi 380/440 heating my house. I'm pretty happy with it but I have never had a newer stove to compare it to.
I am not really worried about overall wood consumption but if it gets me significantly longer burn times, it may be worth it. If the Englander won't make it through the night but the drolet will, it might be what I have to do. I was hoping to get something less expensive until I had time and $ to upgrade to an OWB that could heat both greenhouses and possibly my house. Is 3000$ starting to approach on OWB pricing? Especially after you consider another 1500+ for the pellet stove to heat my other greenhouse.
I know the best greenhouse heat is root zone heating with pex.

Well I just went to clean my 25+ year old lopi 380/440 (old endeavor) and the only air tube is broken in half. The blower also died when I went to go start it up this year. Considering it's age it might not be worth fixing. Replacing the house stove with a new 2000$+ endeavor, wood furnace and a pellet stove with auto ignition. It's getting me close to wood boiler pricing. I have existing ducting in my house for propane. Not to mention, I am only at that house maybe one day a week during the winter so it would be my grounds keeper loading up the stoves. It might be easier for him to keep an OWB fed then a pellet stove and a wood furnace. My neighbor at that house is a retired plumber and offered to help with install.

So I figured out the small greenhouse. Pellet stove on thermostat someone had recommended here. It's really working great. I think I decided on a yukon polar oil/wood for the big greenhouse. My house is off grid and I have a 500 gallon off road diesel tank that I could share with the furnace. This seems like the right move.
There is a used yukon polar for sale here for 2500. My question is, what should I be looking for when I go to look at the furnace? Any weak points? It is older, have the polars changed much over the years?
My other options would be a new polar, or a pellet furnace.
Thanks!