Help keeping my truck cool
I have a 18' old fed ex truck that has been converted to a food truck. It has the aluminum exterior, 2x2 square tubing for studs and stainless on the interior. Summer is about over but I have to make some changes for next year or we will not be able to run it during the hottest part of the summer. I am in Oklahoma and on our 95 degree plus days, the interior of my truck is usually around 104 to 111 degrees. I can live with it but my wife is very sensitive to heat. She's had a couple of heat strokes in the past. We have one roof mounted Coleman 13.5K ac which does no good besides blow cold air on you. I also have to rv fans that input about 1800 cfm to balance out what my exhaust hood takes out. For equipment I am running: (all propane) 3 hole warmer, 36" griddle and 2-35lb fryers. I have painted the top fiberglass roof with a reflective paint.
I have done a lot of reading on Road Food.com and can not come up with a straight answer. Do I insulate or not? Floors, walls, and ceiling? What kind of insulation? Spray foam? Foam Sheets? Batting? I don't want to spend a ton of money but money is not a huge hindrance. I don't mind putting in a second a/c but only if it will do good, I do have the available wattage. Any other options?