Sounds like you are on the right track.
#1. I don't think anyone needs a whole lotta HP. These cars are essentially a GoKart with a V-8. The BigBlock Cars can sound really c
l but that is a whole lotta extra money & A mild small block with Webers is Damn Quick! I don't have any experience driving BigBlock Cobra's but I'm told the lighter Small Block cars are also more nimble(Maybe someone can chime in here).
#2. If you fancy an FIA car, keep your eyes open. I've seen ERA's in that price range when the market was good. At the least, if you you decide you want more power you can build another block up. The quality of the car, If you buy an ERA, should be up to anyone's standards.