TL;DR - No, don't buy the kit. Just go to the hardware store.
Some comments -- https://sites.google.com/site/autocockertests/
so you know I am not making this stuff up from "feel".
1. You don't need a valve spring. Unless you have shortened the stem and don't want it to fall into the valve chamber. No valve spring = the lightest possible spring so you are not having to work against that at all. So don't waste money buying one online. Some of my favorite springs are from cheap mechanical pens.
2. You can buy springs at a hardware store, they don't have to be the exact diameter and length of the stock ones. For the cost of a "kit" you can get all sorts of stiffnesses to play with (if the store is good). And you can have them today.
3. If you have orings on your bolt the forwardmost one is does the bulk of the work, remove the others, or remove them all. You will have to turn in the IVG a bit to compensate but the action will feel much smoother. Don't waste money on a different bolt until you just want to buy something for the fun of it.
4. Valve pins, where the hammer makes contact are all way longer than they need to be. When the hammer strikes the valve it just opens it a tiny bit. Depending how far back your hammer is when the sear catches it, the distance between that and when the hammer strikes the pin could be too short to get the most efficiency from your hammer spring. It is an easy change to take off a chunk from the valve stem. This can make a huge difference on some guns, on a Superbolt for example you really need to do this.
5. Don't waste money on a different hammer. Hammer weight won't make a difference. I have tested this.
6. The most efficient valve design has a small internal diameter incoming and outgoing. And efficient means you can back off the IVG more = lighter pump stroke. The CCM valve is a good size. Also all the old Autococker valves are good (baccipaintball.com). Anything that advertises "high flow" sucks. And I should add that this statement is accurate for regulated compressed air, the old super small ID valves just sweetspot a little higher, like at 350psi (total, not plus), I am forgetting exactly.
a. remove the valve spring (put in one from a pen if you have that)
b. cut the valve stem
c. get some hammer springs at the hardware store (if that is your issue, if you have a fairly light one and you have the IVG turned in a bunch then you have that room to work with)
d. take off any orings on the bolt
e. order a small ID valve, then re sweet spot
Also I would get springs for the slide trigger while at the store, to get that nice and light (while also crisp).