Just make sure you get an inverter that inputs 120v and reduces to 12v.
The other option that has worked, and is cheaper than all get out (free if you have an extra one laying around) is to find a power cord that reduced 120v to 12-14v for the device it runs. You know, one of those cords with the black box at the one end where the plugs stick out. An AC adapter like this:
Buddy of mine uses one in his fish house and has had no problems.
Get yourself some custom split wire loom, this stuff:
To cover all the wires (depending on how your setting it up) or depending on how your fabing up your control head housing/box. You could even fashion up some audio and even power outputs with these:
or similar.
Good luck!