RPM changes are made by increasing/decreasing the weight in the primary arms/weights. There are different weight rivets that can be placed in the arms to achieve what is needed. WOT rpm adjustment is usually made by changing weight in the outer arm hole. Reduce WOT RPM by adding weight, increase WOT RPM by reducing weight. The stock springs work fine in mine, which is a g-w-g primary and green secondary. The stock helix also will work, which is a 45°, but I like a 47° helix so that it takes a little less weight in the primary arms and gives me a nice backshift. I'm also using the stock arms in the primary, which are 8dn-10's.
I have SLP flo-rites in the dash, so my weight setup won't be the same as yours. If I remember right I'm running 3.6gram rivets in both the inner and outer holes.
There are too many variables for any kit to get you "spot on", but they can get you close if you go that route, but you'll still more than likely end up needing to do some fine tuning on the weights to get your RPM dialed in to the sweet spot.