Since you're using a PitBoss I'm assuming you're not doing this legally...ie with the authorization of your local / county health department?
Something to consider is that if you do upgrade to a larger piece of equipment that brings more eyes to your endeavor. In my experience in North Carolina health departments absolutely do not want to see offset smokers...what they want to see is stainless steel. There's not a whole lot of offset smokers which are stainless, and those which are tend to be exorbitant in terms of price.
Figure out how you want to move forward. All this being said the people, ie the customers, LOVE to see offset smokers because they can see the wood fire and the smell lures them in. I cooked all my food in my trailer out front of my house, and would travel from my house to the cook site with the food in hot hold. When I got to the cook site first thing I did was fire up the smoker again and toss on just a couple wings. This got the smell of the meat and the smell of the wood fire wafting, and people would salivate in line waiting for their food.
When it comes to larger offsets I'm 100% on the side of putting them on a trailer. It just makes them so much easier to move, and if you do end up getting bigger catering jobs people want to see the food on the smoker (in my experience, of course).
Good luck moving forward.
