my alarm options? opinion needed

I have a 1995 Z28 that came with the factory keyless entry. I bought the car used a few years ago and the original owner had an after market alarm installed in 1995. So the alarm is a bit dated I guess. As it sits right now the shock sensor needs to be replaced as I took it off to paint it and its guts fell out...And the remote needs a new battery. I went to batteries plus and they couldn't find anything to fit in the remote. So my options are to replace the shock sensor and try and find a battery for the remote or get a completely new alarm. I am by no means an alarm expert so I don't know if i would be able to do a new system my self or not. Would take to a professional if needed. The current shock sensor is a one wire unit if that helps anyone. Give me your opinions on what to do.

Thanks

Check into the Ravelco anti-theft device. It is not an alarm, as nobody pays attention to them anyways, it immobilizes your car. The thief CANNOT get it started when the 16 pin plug is removed.
Undefeated in over 4 million installs!

Main website...www.ravelco.com then look for dealers in your area.

Im not so worried about theft as the fact, I currently don't have keyless entry because i cannot find the correct battery.