TPMS system

Having taking the rocket 111 off the road for the winter I'm looking to do some work on the bike, one of these is trying to find the best type of tyre pressure monitoring system. Have this on my car its a great aid when the TPMS goes off saying the pressure is low on a given wheel so I'm looking for the same type of thing for the Rocket, so has anyone fitted this to the bikes as an upgrade accessory. Looking on ebay you can get some for around £18.00 upwards and it just looks like a dust cap linked via Bluetooth display so are these any good or are there other system types like car valves.

Amazon has them for about $60.00 that have a handlebar mount. All of them will use a cap vice internal sensor.