I give you credit for considering such a big challenge but here is a few things to consider...
Unless you have some cool tricks up your sleave, you will not be able to have or keep the Loins at 145° while the Hams and Shoulders get to 195°, you need more like 200 to 205° for pulling and the least amount of waste. A Reverse Flow smoker is really good at maintaining even heat across the whole unit. So even with the Sausage Stuffing, great idea for moisture retention by the way, the whole hog will see the same temps end to end. To even try to get different temps in the loin and the rest of the hog, you need a set up where you can have a hotter bed of coals under the shoulders and hams while having no or very little heat under the loins. Additionally cooking to an IT of 195°, I assume you are thinking about Slicing as at this IT it won't pull. Trying to slice will only give about a 30% yield. That is with a very sharp knife, excellent knife skills and LOTS of time. If the hog is the only meat, you will need about 250- 5 ounce portions for sandwiches, some will want 2. For Plated Sliced Pork you will need about 225-8 ounce portions. Here is the Math...
Sliced and Plated Pork...225 Portions X 8 ounces ea. = 1800 ounces / 16 ounces per Lb = 112.5 Pounds Cooked and Sliced Pork. 112.5 Pounds / .3 yield = 375 pounds of Raw Hog to feed 200 people!
Let's try Sandwiches... 250 portions X 5 oz ea. = 1250 oz. / 16 oz per Lb = 78 Pounds Cooked and sliced Pork. 78Lb / .3 yield = 260 pounds of Raw Hog to feed 200 people.
Lets go with Pulled Pork, with a 50% Yield...
PP Plated...225 portions X 8 oz ea = 1800 oz / 16 = 112.5 pounds cooked PP 112.5 Lbs / .5 yield = 225 Pounds of Raw Hog to feed 200 People.
PP Sandwiches...250 portions X 5 oz ea = 1250 oz / 16 = 78 pounds cooked PP 78 Lbs / .5 yield = 156 Pounds of Raw Hog to feed 200 People.
To sum it up. The Hogs need to be Headless as they are only of value for Pulled Pork...
Sliced and Plated you need to cook ...375 Pounds of Hog.
Sliced Sandwices you need to cook... 260 Pounds of Hog.
Pulled Pork, Plated you will need to cook....225 Pounds of Hog.
Pulled Pork Sandwiches you will need to cook...156 Pounds of Hog.
Is your Smoker going to handle this much meat?
Do you have the skill set to Smoke this much meat and keep the IT' s where you want 145° and 195°?
Can you Slice all that meat and have the equipment to Hold the meat Hot while you slice?
What are going to do with the 2/3 weight of Waste, that's good meat left on the bone as every part can't be sliced, bones, fat and skin?
Do you have or can Rent the number of Chafing Dishes to keep all this meat Hot while people are being served?
Pay wise, if your friend had this catered by a Pro, she would pay $25 and hour (4 hour Min) for each worker plus cost of Food and Equipment. If you want to do her a favor, charge $10 to $15 an hour. You are attempting a lot of work here...JJ