AU2 Alarm Upgrade

My sound system on my car is starting to get a little expensive ($2000+ :s)

Anyways, Can anyone recommend a decent alarm system that will stop wannabe crooks and/or stupid kids from breaking into my car? I don't plan on stopping anyone who knows what they are doing, as thats what insurance is for. Something that when any doors are touched will go off, or if boot/doors/boonet or anything is opened/kicked in/smashed.

Will it take over from my current keyless entry stuff?

No idea on budget as I'm not sure how much decent alarms go for...

Cheers