Get the Factory Pro, don't waste your time or money on anything else. They only have one kit (with optional jets), so their Stage 1 and Stage 3 are the same. They actually created different stages on their website because people kept asking them for Stage 3 kits, so they just market the same kit as stage 3 so there is less people calling to ask.
The Factory Pro needle has the best design, this is what makes their kit the best. They also use factory (keihin) style jets, unlike Dynojet (from my understanding). So, with Factory Pro, you can buy additional jets designed for our carb. I got my extras as www.jetsareus.com
that I brought with me to my dyno tuner.
As I'm sure you will hear, you do not need to dyno tune, you can use the carb tuning guide in this forum. I wanted to get a more accurate setup so spent about $350 getting a Dyno tune.