I've been able to make a fair bit of progress on this front. Jones Brown does provide the kind of coverage that I think we're looking for. Basically, they provide coverage for HPDE, lapping events and some timed events. It is designed to cover damage to the vehicle on the track where regular car insurance may not be available.
In our preliminary conversations, the premium does seem high - 25% deductible with a $1,000 minimum premium for an individual with no cap on the value of the vehicle since the premium is based on the stated value. That being said, prior experience and having a group apply should help bring down some of the costs. I don't how many events the cost above covers. I am assuming its three since that is what I discussed with them to this point. The insurance will be valid throughout North America.
I'll be back in Toronto next week, and should have hard numbers to share with everyone then.