Guys.. 95% of the time ADSL is not an issue. I used to manage the service area of a company that had a large customer base of security systems both monitored and not. Most of the issues were with Telstra faults and dickheads cancelling lines thinking they were saving money.
We used most major brands of alarm and for cost and effectiveness, you cant go past NESS. Mostly aussie made and easy to program etc.
Just as a side, most people believe the cops take their time getting to alarm calls. Listening on my scanner, they do their best to get there and its usually within 1/2 hr of the call even if the person is on holidays in Mandurah and no one is home.
Anyway. with the NESS you can get it to monitor to a central station or to your mobile. Make sure you put VKI as the last contact on your list of callers on alarm and they will eventually get to you.

Cheers..