Eddie,
As a mater of fact I do have some expierance with making an alarm system, and partally automating my garage. I used a Micro 1 because we had a few sitting around at work and stopped using them so I took a couple home and liinked them togeather for more I/O. I bought motion detectors from Radio Shack for in the garage, and a switch on the ovhead, and side doors. Opening one of the doors would turn on the lights, and compleate a circuit to the t-stat and air compressor. The motion detectors would keep reseting a timer to keep everything going. If I were gone for about 15 minutes(999 seconds), the alarm would set it's self. I had a keypad in the house to set-rst the alarm system, or warm up the garage.
I placed high brightness leds in the overhangs (garage & house) that would flash if the alarm was tripped, or would stay on steady if the alarm system was set. They were so obivious that everybody driving by would see that I had an alarm system. This turnd out to be the biggest factor of all. One weekend when I went hunting, someone went into the garages on both sides of me and ripped off lawnmowers, and a power washer etc.. My garage, and house were untouched. What really suppriesed me is that my lawnmower was in a unlocked/unalarmed shed and they didnt even bother with that.
I no longer have a dream garage because I got married, and moved to a house with an attached garage which is now filled with bicycles, bigwheels, peddle cars, a big red Contenntal etc.. My wife and kids now have a dream garage ad now I'm SOL.