Work lights facing rearward in the back of the van. A couple of decent LED lights you can use to work at night. Also, an optional dome light or two. When the van has racks and bins inside, the side mounted dome light, is obscured and not as useful.
I will try to mount a dome light or two in the "ceiling" of my TC. I will also try to place a power outlet on the right rear quarter. There is a hole already there and I bet there is a power plug somewhere inside the panel there. I can mount a power converter once I have that plug and even use a small compressor or Dremel tool, solder iron, etc.