This is the one I bought last year:
http://www.amazon.com/gp/product/B002L9A4BI/ref=oh_details_o03_s00_i00?ie=UTF8&psc=1
You just bring a big pot to fill with water and then stick the hose in the pot. I heated up water at night on a camping stove and it was soooo nice to be able to take a warm shower at the end of the night. You have to buy the privacy tent separately, but its pretty cheap on Amazon as well. DON'T buy the big water bag one that you have to hang from something because the privacy tent isn't strong enough to hold it. With this one you can just stick the hose through the loop at the top of the tent and ta-da! You're own private, shower. It seriously saved my groups life last year.