Well, if you're determined to follow your dreams, then who would we be to stand in your way. Just understand that you asked for it!
For shoulders, butts, and brisket I'd have to be dragged away from a Cookshack smoker. They will make simple, largely foolproof work of these cuts. An FEC 300, or maybe even the 100 would likely be all you'd need for chicken, turkey, and such. Sausage and ribs will work well in either a CS or an FEC. What you will need will depend on volume, cook cycles, and product mix. Some of these things won't be apparent until you're in business.
A CS SM260 and an FEC 100 would offer great versatility and redundancy in a compact package, at a reasonable cost to purchase and operate. Later, additional units can be added if necessary.
I still see some restaurants operating with big offset pits burning logs and I just shake my head. I can match their product quality every day, do so easily, and at a lower cost. Welcome to the 21st century.
If you follow through with your plans, you'll see why conservation of energy(your energy) is so important. Cookshack smokers make a difficult task as easy as it can be.