It's not a bad idea business wise.... but I like to plow!!
I also wouldnt want to be caught in a situation where I didn't have a truck to plow with. What if If a customer calls and you cant get ahold of your guys beacuse of some crazzy reason and you dont have a truck. However being on top of the maintenance thing is always a good thing.
I'd hire a secretary and a mechanic if it were me.