I personally do not care for Kydex Holsters. I have been using a Lobo Enhanced Pancake for my 4" 64.
I just got my 686-5 completed. I have an Enhanced Avenger on order for it.
The best source for Safariland Comp III Speed Loaders is the Speed Loader Store. Free Shipping. I have 10 each for both my K and L Frame revolvers.
Not being totally happy with the selection or price on Kydex Speedloader Pouches on the market, I have started to make my own Kydex Pouches.
The Midway Rectangular Pistol Case has magazine slots for 7 magazines. Guess what the Safariland Comp III speedloaders fit in them just fine, even loaded.
For ammunition I reload using 4.7 grains of Unique under a 158 Round Nose. That is well over the new IDPA 105 Power Factor. A consideration is Steel Knock Down Targets. The 4.7 load takes over steel just fine. The steel is supposed to be calibrated to go down with the 105 pop gun load. In real life the steel might get out of calibration when set up on uneven ground. Especially with new help resetting the steel.