I always make my own first aid kits. From what I've seen, premade kits give you a lot of nice stuff, much of which you'll never use. I carry a first aid kit with me probably 80% of the time, all day, every day. I know, sounds silly. I've used it often and never regretted carrying it.
For 50 dollars, a trip to Kmart or the local drug store can assemble you a very nice, work specific first aid kit. And this way you won't be paying for the small tube of itch-soother!
Triple antibiotics, Nexcare Waterproof bandaids, much gauze, athletic tape, then a few extras.
Call the local hospital or red cross and take a first aid class. You can learn a lot from that.
Know how to use what you have available....much like a chainsaw!
love
nick