Immobiliser fitting Bridgend or Cardiff
 

I'm looking to get an immobiliser fitted to my classic sti ra. Where is a good place to go in the Bridgend or Cardiff area? I'm not too bothered about an alarm as its always parked in my garage over night etc. Just worry a bit of I go out for a drive and leave it parked up somewhere, it will be gone when I return. It has central locking so would this help if I did go for an alarm?

Many thanks