I used a commercial policy IIRC, it was through Progressive. I do remember having some trouble finding an agent who wanted to cover it, but the local progressive office came through at the last minute.
I switched to commercial for private use when I got it home and had time to shop around. Got that through National General, but it was also underwritten by Progressive.
Call Kelly Newsome from All State. You can search for her info on here. She will get you in touch with an agent in your area and you will have insurance same day.
i have mine through NATIONWIDE in NC and it is just a phone call for me.
my original bus is insured as a bus for personal use and for the one i purchased and picked up today was just a phone call earlier this week with the VIN number to get a letter of insurance coverage with no problems before i ever purchased it.