http://www.amazon.com/SUPERNIGHT-Waterproof-300LEDs-Flexible-Controller/dp/B00B2F3KDQ/ref=sr_1_5?ie=UTF8&qid=1399132639&sr=8-5&keywords=12v+led+strip+outdoorThis is similar to the one I installed on our camper. It does wire straight to 12V. The 12V plugs into the controller box (little white box in upper right) using a barrel-type plug like you see on most AC-DC adapter boxes. The plug is not included. I'm sure you could get one from Radio Shack but I just chopped the end off of an old AC adapter and ran that straight to 12v.
This might not apply to many people, but for my 12V I went down the inside of the vertical awning rail (the part permanently affixed to the trailer). There was a channel that the awning power goes down. From there I went under the trailer and through the floor to tap into my batteries.