Consider a system with a two-way remote, such as manufactured by Clifford/Viper. All alarm systems tend to sound the same and are largely ignored in neighborhoods where false alarms abound, but hearing the chirp coming from your keychain sure gets your attention. Transmit range on a two-way system is typically 1/2 to 3/4 mile, so it's useful if your rig is parked only sorta nearby.
The downside of a two-way system is that they will consume additional battery power - mine draws an additional 40 mA after everything in the RV stabilizes - about 4-5 minutes after the doors have been locked and the alarm has been armed.
False alarms can generally be eliminated by properly adjusting the threshold of the glass break sensor, so installation by someone knowledgeable about your particular brand is essential. I had my system installed by a local independent car stereo sales/installation shop that I'd found previously through Yelp when I was looking for someone to replace the GPS/sound system.