Yes, you should keep security biz separate for both insurance as well as accounting purposes (RMR).

I second Kirschenbaum.
https://www.kirschenbaumesq.com/

Go here to find any contract you might need, as well as legal issues and articles.
[Link: kirschenbaumesq.com]

You most likely will find recommendations for insurance companies. Also, your central station should have good recommendations for you.

Some great articles in there - answering questions from the industry, talking about legal issues of the day. I subscribe to his newsletter, which often has some great tidbits. YOu can subscribe here:
[Link: kirschenbaumesq.com]