For insurance, there are a couple of options. One is to "schedule" your bike on your Homeowner's/Renter's policy, We've helped a few customers work with their insurance company to establish the value of the bike when they've needed to schedule the bike or make a claim. You would call your insurance company, or your agent if you have your policy through an agency.
The other is a dedicated bicycle insurance company. A number of our customers have worked with this company and have had good service from them: Velosurance.