Matt, it appears that you are going the air handler route in your shop and I understand your rationale and the other issues involved in your case.
I would however like to point out that a system using radiators and TRV's is much more "friendly" for any boiler system using solid fuel as the heat source and especially those that do not utilize storage.
This is the main reason.
Visualize your boiler standing there with a load of wood in it, up to temp but idling. Now introduce a load that can use up about half the boilers output at full throttle. An "instant" load that comes on full draw all at once like an air handler. In your case the boiler will pump out 180-200Kbtu and the airhandler may draw 100K. Here's the sequence that I see time and again and it leads to poor performance and other problems.
1. The air handler/furnace with a coil, kicks on and introduces a substantial load.
2. Assume that the boiler is in an idling state of operation.
3. Heat is drawn off and water temp drops after a couple minutes.
4. The aquastat on the boiler starts the combustion process after the load is present.
5. Being that it takes a few minutes to get a solid fuel fire going, much less up to full output levels, the boiler water temp drops to unsatisfactory levels. (if a mixing device or pumped bypass is present you now have greatly reduced heat or even no heat going to the air handler)
6. The boiler catches up after maybe 10-15 minutes of getting itself up to full burn and satisfying the heat demand.
7. The boiler cycles down wasting a fair amount of heat and inertia because the load is gone as with the same "speed" as it was introduced.
Now let's look at a Radiator/TRV system
1. Assume you have iron column type or steel panel rads
2. The TRV's are constantly providing heat proportional to the loss of the space being heated. They are never "off".
3. Heating load on the boiler is constant, allowing the fire to cycle at a very even rate, maintain temperature and never get behind the curve.
4. Water temps and combustion temps remain in a much narrower range greatly enhancing efficiency.
a
Proportional heating beats forced air any day of the week and twice on Sunday.