I like Kraigwy am also running a 4" 64. Mine was a Police/Guard trade in 64-3 project gun. I bought this one planning on making it an IDPA SSR revolver.
I lucked out and got a mechanically very good one with a little pitting under the grips. I did some polishing on the internals and added a Wolfe Spring Kit. I also painted the upper 2/3 of the front sight with Green Sight Brite sight paint. I would try some very bright Green Finger Nail polish from the Dollar Store first. I then had Ron Power "Power Custom" give it a going over. Chamfeded Chambers, and adjusted everything for better than factory new function. It is now a K Frame Swiss Watch.
Grips: I am currently running Hogue rubber on it. I will probably change to some wood finger groove combats sooner or later. I have been slowly changing my S&W revolvers all back to nice wood grips. Considering you have a K Frame Round Butt, I would go with a good carry grip. I have Checkered Rosewood Finger Groove Combat S&W grips on my 66 Snub. I like them pretty well for a K Round Butt grip.
Speedloaders: I use Safariland Comp III Speed Loaders. Midway runs them on sale now and again. A good time to add a few more to the old collection. I am up to 8 Comp III's at the moment. Note: You can load at "Load and Make Ready" with HKS, or Comp II Speedloaders, (No need for speed). You only need the Comp III's for timed reloads.
Note: Mine are still bone stock. I have not done any tuning on them.
Speed Loader Carrier: You will need a speedloader carrier. North Mountain IDPA Compliant is one of the best. You will need atleast 2.
Holster: I use a Lobo Enhanced Pancake holster with Optional Inner Hammer Shield. This is my every day carry holster, as well as my match holster. I have 8 Lobo Pancake holsters at the moment, if that gives you an idea how well I like them.
Ammunition: For ammo I am running 158 Round Nose Lead reloads. My current load is 4.7 Unique. Reloading on the Dillon 550B using Dillon Dies. I store my match ammo in clear 2 pound plastic jugs that Nuts come in.
Your HKS speedloaders will work ok, however after using a Comp III for a very short while you will see an improvement in your reload time. Probably a question of how compedative you are going to be.
Practice/Training: If you conceal carry, and are using the match for practice & training by all means use the speedloaders, or speed strips you will carry to reload with. My brother reloads his 3" GP100 with speed strips some of the time in matches, because that is what he conceal carries to reload with. Another thing to consider Tuff Products Quick Strips come in Orange. They are handier to locate on the ground after a speed reload.
I have several HKS, as well as Comp II speedloaders. I keep buying used ones at gun shows. A while back I got a couple Comp I or II speedloaders that were for me a goofie size. I finally figured out they were for a Colt Trooper or Ruger Six series. I have a buddy down the road who Conceal Carries a Speed Six Snub who is now using them. I also have several Tuff Products Quick Strips in 5, 6, 7, and 8 shot versions.
Have fun shooting with your 3" Model 65. You have a great all round carry revolver.
Bob