I would go with compustar great i mean great alarm a friend of mine has it and i used his car for a month while he was on a trip i loved it. The thing will has a 6000 feet range (2WSS models) and and u don't need to press the button to unlock as you get close to your car the alarm recognizes the remote and it disarm itself and vice versa. Has a nice colored LCD screen too.
www.compustar.org best price would be ebay
The only disavantages is u can easily go through a new set of batteries every month