Why not take multiple battery powered speakers, and take a power inverter to plug them into when they run low on their own battery?
You can keep your laptop, and mixer plugged into power inverter whole time...that kind of sips power so the power inverter should last a long time.
As for lighting use all battery powered par lights.
One of these manufacturers need to create battery powered mixers, and a battery powered SUB (Put an extra batter or two in there to keep it going). Also, ADJ or Chauvet need to creat a battery powered all in one light effect system....For example a ADJ BoomBOX FX "GO" version where it's ran on a rechargeable battery, or a Chauvet Gig Bar "Unplugged" version.
This I believe is where they need to go to create more sales. The lights they have been coming out with last couple years are not having DJs lined up to buy them because we want a new feature that makes it even easier, and more convenient...Battery Power! (That is long lasting)