So you only need your bike to be protected for the next 6 months? Why not just keep a careful eye on it when your out? Even the best security system won't stop some random deushce coming up and trying to sit on it or fuck with it.
full coverage would cost you out the ass, but would insure your replacement if it doesn't come back to you.
As for alarm/gps, I'll say this much. I went to Indy for the indianapolis motoGP, got fucked up, way too drunk to ride(even walk..) so I left my girl in the heart of downtown one night, actually left my jacket and helmet strapped to it too. I whole heartedly believe if my bike didn't have a perimeter sensor on it, that my jacket would have been lifted and maybe even my bike..so for the 3-400$ I spent on my SR-i1100 or whatever, that has a shock/tilt/perimeter/and gps, has IMO already paid for itself.
"Do or Do not, There is no Try"