Advice needed re: heating system plans

I will be installing a new heating system this summer and am looking for some input. I am leaning toward a wood/oil combination furnace, but have some concerns:

1. Some seem to feel multi-fuel units sacrifice efficiency. Better to get a new oil furnace and a separate wood add-on?

2. Will I get the BTUs I need? ~3500 square feet of 1860s farm house in central Maine...I need some juice. Models like Charmaster and Yukon Polar claim they can get it done, but I don't want to find out the hard way they don't quite do it.

Any advice is welcome. If there is a bigger badder furnace out there that I haven't stumbled across, please let me know.

Thanks for the replies. I am looking for an indoor furnace. It does look like getting separate units ould open up more wood furnace options, so I'm starting to look that route. I had hoped to find some larger wood-only furnaces out there, but am still finding that most stop at around 100K BTU/3500 sq ft heating capacity. Any higher output models you know of?

I have looked at the Kuuma and the Caddy and they both look pretty nice. The Kuuma website says the larger model produces 30K-40K BTU and would take the place of a 100K BTU oil burner- so I don't think it will have the output I need. The Caddy has a 77% approval rating from recent customers who have registered their product - not exactly shouting its praises - plus a smaller oil burner option than charmaster and lower overall BTU ratings than both charmaster and yukon.

On another note - can anyone with a charmaster tell me about their shipping? This is going to be a big investment for me, and their "if it breaks during shipping that's your problem" policy has me wanting to give my money to someone else. Do they at least crate it well so damage is unlikely?