Installing Tyre Pressure monitors

[glend]

I am getting some new rims (without the tyre pressure monitoring inclusive to the 2007 KJs). The old system doesn't really tell me anything except to put off a chime. I am looking at one of the new systems, like Hunty's or maybe the Tyreguard 400 by daviescraig, which seems a resonable cost.
http://www.daviescraig.com.au/TyreGuard__TPMS-list.aspx

What do people think is the best system for use with a trailer, that provides individual temp and pressure for each wheel plus alarms?

Cheers Glen