Big old deep cycle battery from supercheapauto, run everything directly of that (except for laptop). I'm not afraid of soldering though, so I've made custom cables when needed, put a few cigarette light ports on the end of the cable for compatibility with general stuff (eg USB power adfapters) but everything else I make a cable for using XT60 connectors to connect to the battery.
Edit: this setup lasts multiple nights with a 1600MM cooled, laptop, HEQ5 and assorted other gubbins. However the battery is rather heavy, so I'm glad I'm relatively young.
