Then products are irrelevant, your installer of choice will use their own preferred manufacturers.
They will have trained on that kit so asking them to fit something else is not the best idea.
You should get at least 3 quotes go with the company you feel the most comfortable with, not based on solely the quote price.
I'd usually replace all the electronics, but you don't mention age or models of kit.
If it's a really old Premier I'd bin it anyway.
4 zones, 3 sirens and 3 exits, seems the weirdest system in the world...