There are a plethora of choices for First Aid type kits, where have folks found the best and most comprehensive kits and what can you expect to pay? Everyone's thoughts are appreciated
Basic first aid is good, and any kits can be had from your local pharmacies. If that is all you need, then great.
But if you are serious, I would recommend a formal class. Get some advanced first aid and CPR training. While you are there you will be rubbing shoulders with a lot of professional folks, who can point you in the right direction. You might want to get some basic A&P, and pharmacology. Learn how to use some different basic meds.
FWIW, I keep several first aid bags (that I used in the military) with everything from band aids and splints, to chest tubes, antibiotics and I.V. sets. They are in strategic locations, like my vehicles, my work shop and business. Even better is I have been able to train my family to use the contents as well, and we now have a lot to offer folks around us in an emergency as well.
The best kit will be the one you put together yourself and know how to use.
Don't forget to add a package of Quick Clot to any first aid or trauma kit.
There are some injuries that a compress cannot handle, like a gunshot wound, chainsaw injury, or any arterial hemmorage.