I was at that stage a few months ago. What I was told was cargo van. 18-20 MPG vs 12-14. Not enough 3 & 4 skid loads (C-rate) out there to justify the box truck. Not sure how many skids the box truck could carry, but if it was 5 or 6 then a lot of times companies are gonna call a dock high straight truck.
Mind ya, you may have other information to offer that ya didn't present here. From the nature of your Q though, I'm guessing you'd be better off in a cargo van.