Just make sure you get an inverter that inputs 120v and reduces to 12v.
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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:
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Buddy of mine uses one in his fish house and has had no problems.
Get yourself some custom split wire loom, this stuff:
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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:
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or similar.
Good luck!