I'm looking for a 12v circulator pump for my RV build. This pump will pull hot water from a water heater and circulate it through either 1. fin-tube radiator(s) or 2. an automotive heater core in a closed loop in order to provide hydronic heat in a small van-sized RV.

Design requirements:
* Power source = 12v batteries (not direct PV)
* Power consumption = as low as possible
* Max head = 3 ft max
* Gallons per minute = whatever, just enough to move hot water around
* Loop length = 15 ft max

I've been doing some research online and have a few pump "contenders" so far:

- Hartell MD-17-HEH PV direct pump: not sure on power requirements, 5 GPM
- Ivan Labs "El Sid" SID5PV pump: 5 watts, 2.5 GPM max, 2.2 ft head max
- Ivan Labs "El Sid" SID10B12 pump: 10 watts, 3.3 GPM max, 3.5' head max
- Laing "ecocirc" D5 solar DC pump: 22 watts max (0.25 - 1.46 amps)
- March 893-07 Brushless 12V 1 AMP DC pump: 0.006 hp (about 5 watts), 2.7 GPM max, 10.6' head max
- March 809-PL 12V Mag Drive pump: 0.01 hp (about 7.5 watts), 5 GPM max, 7.1' head max

Am I missing any other low-power usage 12v circ pumps out there?