Need some guidance as to wood boiler or add-on furnace

You can heat 2 buildings, you can shut off, regulate either one. You can go a long distance, but pipe sizing is a must.

If you go the furnace route look up Kuuma Vaporfire 100, best on the market built right in your state.

What stihly said ^^^! And you'll need a whole heck of lot more than just yard clean up to keep up with feeding an outdoor boiler. 'Less you have 'bout a 50 acre yard! OWB is a pretty substantial financial and firewood production commitment. If you do go that route though, DON'T cheap out on the lines! Don't do it, you WILL regret, sooner or later.

Just how big of an issue is cost?

If you figure $20/foot for underground lines for starters - what does that do for your thinking?

Storage is typically used to allow batch burning: light the fire and let the boil run at it's hottest and most efficient until the wood is gone, the btu's not consumed for heating the zones get stored in the tank. Fairly simplistic description but thats the crux of it.
I suppose you could utilize storage with a CB, but that is not really what they are designed for. The CB will have a circ running 24/7 so you would have to incorporate controls/valves to isolate that loop from the storage when the fire cools down.
I would spend some time defining your goals for a heating system: max efficiency from the fuel? minimum wood handling? boiler must be outside or can it be in the basement? what is your budget? if going with an OWB do you see yourself handling 7+ cords of wood annually? how will you feel about having to get leaks in an OWB welded after 10 to 15 years of use (better then average chance any unpressurized boiler will suffer corrosion, can't fight physics), a gasification boiler is definitely more efficient but compared to OWB they require a higher degree of fuel quality (DRY WOOD) and operation skill, ultimate performance is highly dependent on how the entire system is integrated.
Touting the ability burn wet wood as a selling point is kind of regressive. If the goal of burning wood is lower heating costs and stay off the petro crack pipe then wouldn't one want to get as much energy out of each stick of wood as possible? Using up +30% of the available energy to boil off water is not efficient.

Not sure if any of this has answered any of your questions, but this forum is loaded with good sound information and great people willing to help understand it.

How much wood do you want to process & prepare every year?

If 12 cords doesn't scare you off - the OWB might be your option. Did you get a price?

No matter what the salesman will say.. Water does not burn!

To simplify the physics.. You must first steam the water out of the wood to burn it - All that energy is wasted energy NOT going into the hot water to heat your home.

Keep reading. Lots of good info on here.

Well You better love to cut stack and split wood if you want a boiler .. And love trudging in sub zero blizzards to keep it well fed ..Some of those cb and hardy owners in a cold snap can burn a full 4x4x8 cord of wood in one week ! The caddy would be so much more ideal 3 grand versus 10 grand and a third of the woodusage Your house is not big enough to even warrant an owb when a high tech furnace should easily accomplish this id hunt for different insurance and keep. Searching for coverage