Here's my quick response - until you get a response from an expert...

I don't beleive the rules require that you use HANS specific belts (I too, only have the 2007 rule book) - that said, if you're needing to buy belts at the present time, and you're buying your HANS device too (*hint - you should be), then you'd be better off buying HANS specific belts as the HANS is mandatory for 2009.

To my knowledge, the only catch would be that you won't be able to use the HANS belts without also using a HANS device.

The major difference between a HANS belt and a regular one is narrower shoulder straps where they'd go over the HANS. This makes it somewhat less likely that the HANS will come out from under the belts due to mixed/secondary impact forces. Regular belts work just fine, but may have a tendency to hang over the edge of the HANS a bit. Proper mounting of the shoulder straps behind the seat is critical in either case.

That's the first I've seen those 4 belt systems with the body belts and HANS belts, very interesting.

I thought this would be an easy decision....