95% of the time I simply use a lithium jump starter. Much lighter and more compact than a bulky power box.
I had stuff laying around to build my own so I did but use it sparingly on the ice. It gets used for other stuff. It has the standard USB ports, a 12v outlet, lights, voltage meters, etc. Where it differs is that I got my hands on a marine radio with built in speakers. Slapped that in the thing, mounted a small antenna, and a 1″ RAM ball for my camera. If I added up the cost of all the components I have in the thing it would cost around $60 to build. If you have a very, very basic understanding of 12v wiring it makes no sense to overpay for one of these things. Just build your own.