Hi.
I have a Datatool S4 Cat1 Alarm & Immobilser.
Its the best they do which is why I had one installed.
Go to their website :
DATATOOL
Click on where's my nearest dealer and then type in your
post code and it should come up with a list of bike shops
near you.
You can then either contact the shops to see if they have
experience of puuting alarms on HD's or e-mail Datatool to
see if they might recommend someone.
Hope this helps.