IFAK - first aid kit

[Robb]

I should have a IFAK or 2 for the cars and my son and I.
I've never built one, used one, or taken a class.
This will probably be stored in the cars and then then taken during hunting season and fishing / hiking trips.
I seriously doubt I'll ever have to deal with a gunshot wound, but I don't want to totally discount that possibility. Mostly I worry about someone getting laid open with a knife gutting an animal or falling.
I'm mostly interested in just stopping the bleeding, should it ever happen.
I was thinking a small pack, quickclot, the ability to stitch up a wound, tape, gauze...
Should I buy a premade IFAK or make my own? Any thoughts on what I really should have in the pack?
Really any thoughts or insight into what to have would be awesome.
And does anywhere around Denver stock IFAK's?