If you're trying to undercut the competition with a lower-cost solution, I would get rid of the vehicle altogether and just try running a LAN-party rental service.
Buy six 50-inch 4K TVs, 6 PS4 Pros, etc. Promise to come set it up in someone's garage or outside if the weather is good. Target birthday parties, graduation parties, etc. In my experience, small businesses will often do parties at their offices to save money, etc.
If it doesn't work out, you can just sell the stuff on eBay or Craigslist and get back at least half your money. With a custom vehicle you're tying up a lot of capital, and have others have said, it seems like they use larger trailers for a reason.
