Agreed, if someone is prepared to fit a system they dont support, train on etc id run a mile.
If risco is what you want, look for companies that specialise in risco.
But as the service etc is provided by the installer id recomend you find the installer you are happy with first. The best kit can be installed badly and result in unreliability.
Also if you specify the equipment if you have any issues then the installer will quite rightly say, its the gear you wanted.
We all have our preffered kit that we test and setup a certain way.