The
is what I use. It's small, light weight, costs about $60-70 (depending on version), and takes up to 1080p at 30 or 60fps. You can modify the cam with a wide angle lens, turn it upside down, use it as a car dashcam instead, take single photos with it, and many other modifications easily done through software. The only part it misses is your recording time. The best of them with larger batteries last about 2-1/2 hours. The base model gets around 90-mins.
To get your 3-4 hour requirement, you may want to find an action cam with easily-swappable batteries, then just carry a spare with you. when the first runs out, pop the new one in and continue. (The Mobius' batteries really aren't ready to be swapped out on the road. Better done while at a desktop with some very small screwdrivers and steady hands.) I did this with my first one, a
Contour, which had incredibly easy battery swapping. I don't recommend them now, however, as the company does not do customer service very well (their mount failed, causing damage to my very pricey cam and I heard crickets back).