Ricky,
If you are planning on leasing your tractor to a company - you can usually get a group rate on your insurance through that company. If you call the recruiting departments of the companies that sponsor this site, they can give you an insurance quote over the phone based on the amount of replacement value you would need your tractor insured for.
Keep in mind that generally your Million dollars of non-trucking liability (deadhead/bobtail) insurance will be included in this rate as well - but be sure to ask.
I hope this helps point you in the direction you are wishing to go...
Scott