Scott,
The following is my opinion only, and represents my view, as a relative newbie as well, of the speedster manufacturers. Intermeccanica is the top of the line builder. They build a tube frame car with roll up windows, etc. and will customize the car with anything you want. They are also the most expensive. Next down the line, in my opinion, is JPS who also build an excellent car, but use a VW pan. I don't think they are quite as technically advanced, and won't customize as much as Henry will at IM. I'm sure I will be corrected on that, but that's my opinion from talking to both John and Henry. Thirdly there is Kirk and Vintage Speedsters. Nothing against the VS cars, but they pump out way more cars in a year than JPS and IM put together and the result is some great cars, and some not so great cars.
One thing I did that was very informative was to go to the "registry" section of this web site and sort by 'manufacturer'. Then go through and read the comments from the Vintage Speedster owners, and the JPS owners, and the Intermeccanica owners. The JPS and IM owners are all pretty happy, the VS owners are about half and half. That said, you make more cars, it just make sense that it will appear there are more problems. The percentage of problems between all builders may actually be about the same...though that's not what I saw in the registry. In my opinion, IM makes the best cars, and JPS is a close second, and a bunch less money.
Let the flame wars begin ;-)