Get something like this:
http://www.amazon.com/BESTEK®-outle...1431619489&sr=8-6&keywords=car+power+inverter
With one of these:
http://www.amazon.com/Jebao-PP300LV...TF8&qid=1431619536&sr=8-1&keywords=40GPH+pump
And one of these:
http://www.amazon.com/EHEIM-Jager-A...TF8&qid=1431619569&sr=8-2&keywords=50W+heater
Cooler (I have this one):
http://www.amazon.com/Coleman-30000...qid=1431619663&sr=1-2&keywords=coleman+cooler
Airstone is up to you, I found just a water pump was enough for my uses. (I move my tank every semester right now). Just throw it all in a decent sized cooler and you should be good to go, I use 50/50 freshly mixed SW and old tank water, with a dose of prime for my 2 hour trip, in case for some reason I need to keep fish and corals in it longer than a few hours. If you can add some small rocks this will help too, nothing huge that can topple over and kill a fish but small rubble pieces are good to use and would let you run the cooler overnight. With your tang just do like 8-10" of water. My clown is happy with 5-8", if you have a special needs fish like a Leopard wrasse this would allow you to dump in 2" of sand as well for them to hide in.
I had to stop at a hotel once with the fish in the cooler and it was no problem because I had pellets with me, and I had some rubble pieces in the cooler so fish were fine after being in the cooler for about 48 hours. Foraging fish like mandarins or the like will also like rubble pieces as it will let them forage.