Cycleman,
I would suggest that you might want to follow Kirk's lead. He is building a car that can also be used in another series, IT. The new national rules are meant to be IT friendly. While I feel that you will be happy running the HC, it will give you more flexibility. It will also make your car more marketable should you decide to sell it. The Si model seems to be the hot ticket in ITA.
On the other hand, one of the cool things about the HC, is that it provides a place where models that aren't classed or classed where they will be an underdog with SCCA, a place to run. If you have a model that your really like, you can race it. e.g. the car I race would not do very well against the other cars in ITS. It should do fine in HC.