To those who think I am mad. I can get the system I want for £99 more than the cost of parts if I have it fitted. The cash is neither here nor nor there. When you retire, things you hated in the past become very tolerable,......believe it or not, cutting the grass.
If we do nothing, we stagnate, hence the reason I would like to fit myself, though my knowledge of alarms stopped 35 years ago. Learning is good.