$30K to spend? Unless you are a good & resourseful mechanic/builder. I would strongly suggest that you buy the best used AC on the market you can find for the 30K you have. Then refit the roadster to your liking as funds allow. IMHO, the min. cash required to build a quality AC is 40K. Saying you are a good builder, painter, mechanic, etc. All that being said, the only kit for you as a builder would be FFR MKIV. For the cash you have. It's the best value & quality (kit=20K complete) for 30K hands down. As to top 5?
1. KMC
2. CSX
3. ERA
4. ALL
5. THE REST
WELCOME THE THE ADDICTION!! 
THERE IS NO CURE 