What I would do is shop around online by typing in "trucking deadhead insurance" or "bobtail insurance" into Altavista or any other search engine. That way you can call the individual places and see if they will insure you, and get rate quotes for the type of vehicle you want to insure.
It would be hard for me to just say "go with company X" because I use them, as they might not cover your state or an inexperienced driver. I used to use a place called TrueNorth out of Iowa that used to cover all states and all drivers, but recently dropped NY where I live, and had to go with Travellers. Good news was Travellers was actually cheaper, but took time to set up and their rate is very definitely based on driving experience.
Anoter place to call is your local big truck dealerships, they can usually recommend an agent for this type of insurance. If leasing on somewhere to do your hotshot loads, you'll need your own collision insurance too- most often one company can cover both the collision and bobtail. My own rate for both of these on a 33k gross D unit runs $234.00 a month- keep in mind that's NY, most other ststes are cheaper.
-Weave-