Do you have an existing broadband service that you can get extended? It's always recommended on here not to cancel an existing service until VM is installed and working, but usually people don't come here and see that until it's too late.
You should bear in mind that there is always a risk in relying totally on broadband for security systems because no broadband service guarantees constant connection. This is something that the sellers of such systems conveniently fail to mention.
VM for example makes no such promise. They have only a scheme to pay some compensation after the first two days without service, but faults often take longer than that to repair.
