I recently purchased and installed a HawksHead tire pressure management system. I looked at several systems in stores and on the internet before choosing this particular brand.
I chose this application because the sensors have changeable batteries. Instead of having to replace a $40 sensor every two years or so, you can replace a $5 battery. It has a one year warranty and I found it quite easy to program and install. I have had it on for about two weeks and have driven over 1700 miles and have found it to be sound and no leaks at the valve stem and sensor.
The company that makes this item is from Canada and the instructions are quite amusing with a few "eh's" thrown in.
If anyone is interested in researching further, the link follows:
http://www.tpms.ca/RVMH.html