What does the car run now? Personally, I'd keep tweeking on it and go fast N/A. It's much more challenging going fast N/A than bolting on nitrous or turbos or blowers IMO. Not that power adders don't provide their own specific issues as well as benefits, but they also add more cost to an initial build. Learning to tune the car to run the best it can N/A with what you have is very satisfying and educational in my book. Whatever you decide, have fun and good luck!