Well, the others have already chimed in about getting some training, so I won't beat that to death here, but they're right on the $. On the other hand, you'd be surprised at how much you already know and is just plain common sense. At the very least, take a basic 1st aid class or better yet a 1st Responder. Usually CPR is included, but if not it's a must have. And when you get/put -together your kit, if it includes any sort of "First Aid Guide," take a few moments and READ IT. When it comes time to use it, even if you don't remember all the specifics, a quick glance at the book will hopefully jar your memory, 'cause you likely won't have time to read it in an emergent situation.
So, now that that's said and done.... as far as the kits you mention, the third one (M-3) might be a good place to start. Also, take a look at what Gall's has to offer in their pre-packaged kits, they're pretty well put together. You can (and likely should) supplement whatever you buy to suit your particular needs and training. The best kit is usually one you have assembled yourself either from scratch or using a prepackaged kit as a base.
I'll leave out the obvious like a box-o-band-aids, single serving packs of Neosporin, antiseptic wipes and the like and hopefully give you a few items that you may not have thought about. Even if you go with one of the prepackaged kits, here are a few goodies that you should consider including, in no particular order:
**PPE equipment. Remember, if it's warm and wet and it's not yours, you don't want it on you.
*Gloves: #1 PPE item. nitrile is best, but latex is acceptable (unless you or your patient has an allergy). Have more than one pair. Doesn't hurt to have quite a few so you can equip others who's assistance you may need.
*Safety glasses: also a part of your PPE,(at the range you'll likely have them on anyway). Bodily fluids can be projected great distances. Unless you're really good at that Matrix move, you will likely get some on you. Best to keep it out of mucous membranes. If there's room, a face mask/eye shield is not a bad investment.
*CPR barrier, such as a pocket-mask. They are out there that are small enough to fit in a keychain sized pouch. I have on of those and a pair of gloves on me all the time.
*Oropharyngeal & Nasopharyngeal Airways: Make sure you ask your instructor about these if for some reason it's not covered.
*Hand-operated suction device. Hard to maintain an airway when it's full of blood or vomit.
*Hand Sanitizer: get one of the alcohol-based gel types. They're great for use after an incident. Also just handy in general. Port-o-lets don't usually have a sink to wash up.
*Eye Wash / (sterile saline). Available in a prepackaged form, useful for irrigating eyes, cooling burns, flushing minor wounds, etc. More than 1 is not a bad idea if you ever have to irrigate an eye. Just an example, a chemical burn to the eyeshould be flushed for a minimum of 20 minutes. 4oz just ain't gonna do it.
*Bottled water. Doesn't hurt to have an extra bottle or two around. Great for heat emergencies, burns, etc.
*Dixie cups: not only for the water, but can be used to stabilize objects impaled in the eye. Make sure no styro, it will crumble and contaminate.
*Dressing materials: 4x4 gauze, tape, a couple of bulky (this is where the Kotex come in handy) dressings, materials for a pressure dressing (check out the "Bloodstopper"), Kerlix (cling), and probably pretty important in our sport, a bio-occlusive dressing (vaseline gauze or foil). Used for that mythical "sucking chest wound".
*QuickClot Dressing: There's still some debate about this stuff, you'll have to make your own decision, but look into it.
*Triangular Bandages / Cravats: for sling and swath
*Oral Glucose: for diabetic emergency. Could also substitute packets of honey.
*Cold Packs: not like the potential for a sprain or strain isn't readily evident.
*Tools: shears, forceps, tweezers. The latter are especially useful.
*Space blanket: shock treatment, shade your patient, etc.
That's about all I can come up with off the top of my head, but with proper training and the willingness to improvise a little, this should get you through 99% of all emergencies you are ever likely to face. If I think of anything else I'll add on later, and feel free to ask any further questions. Hope this helps a bit!