I'd agree with Rick, these can all be good choices that have different features that appeal to slightly different tastes and expectations. My suggestion would be to actually see a CAV, Superformance, RCR, Bailey, ERA etc., talk to the owners and if possible drive and/or ride in one. That can help refine what you're looking for in one of these cars. They definitely are not for everybody and taking some time to determine what you're looking for will save you untold grief down the road.
Besides the chassis, the builder and spec (engine, trans, etc.) selection are very important in an owner's ultimate satisfaction. You can have a miserable experience with a poor quality build or purchasing a used unit that is beset with problems regardless of the chassis brand.
Fortunately, you're in a location that will allow you to contact interested dealers, members of the forum and other owners to see for yourself.