Hello There,
I hope this email finds you well..
I am Danny, a Software Developer from Indonesia ( freelance for now, hoping this business will grow ).
Reading your requirement, I think wordpress CMS would suits your need. (All point 1 to 4). With wordpress, you can even change the layout yourself ( provide you pick a right plugin, I will make a quick video tutorial on how to if needed). Trying to upgrade the old CMS usually doesn't end well and time consuming, especially if the back end was .NET ( which is usually compiled and the SOURCE CODE is being held "hostages" by your previous developer).
Now, my questions are, is there any module that process payment ? You said it is an Insurance Company, and there are products included ? Also, for the quote page, how your staff access the quotation? is it by email?
To make it easier, Do you have a link I can look for ?
Here's my plan,
1. Gather Requirements, that include, your previous website, what you want to keep, or change.
2. Find out which designs that suits you () By pointing you to several website design links / template)
3. Start Developing the website, either by buying template, or works from the scratch. I'd prefer from scratch for flexibility, buying template is "as is", most of my previous clients like to "change this color a bit, resize the button a bit, remove this icon. add some butterfly .." so on so on..
4. Revision
5. and 2 Month Warranty if there's anything not work as supposed to.
Warmest Regards