In terms of mechanical problems, Traeger and FE's are the same operating guts. The FE-100 fits in between all of the "backyard" Traeger models and the commercial models. Although I'm not very familar with commercial Traegers, the big difference is the insulation in the FE's, which translates to fuel efficiency, especially during extreme weather operation. Also, from what I've seen, your shelf space/capacity is greater with the FE (until you get to the commercial units).
The FE would be my choice for your application. As your "small food service operation" grows, you can grow into the FE-2000.
Rod