Cnickgo
Observer
I picked up a AMK kit when I did mountain bike patrol, we added a few extra items including a sand splint. Most of us in the patrol only had basic 1st aid/cpr training and there was a couple of items that I wasn't really
comfortable using, but are theory was there is a chance that there would be someone qualified that would pass by that could help out (that happen alot more than you would think). So I was a mule for the most part carrying supplies and a radio, really the best thing that I could do for someone that was seriously hurt was call 911. We found that doctors/nurses didn't mind helping out in a emergency situation they just didn't want to carry alot of cr#p when they were out riding for fun.
I guess what I'am trying to say is its ok to have more things in a kit, even if you are not qualified to use it, because there is a chance that there will be someone around that is. If your not qualified to use something in the kit then don't use it.
Another company that can put together a good 1st aid kit is Remote Medical.
Sand splint or SAM splint? You have a good point about having qualified people around.
Remote Medical is who I buy my supplies from. Easy website to find and order what I want.