Don’t get the Hero 4 Session if you do long rides as you can’t change batteries. The Hero + should suit as it has wifi so you can use your phone to set shots up and you won’t have the weight or drain of an lcd screen. Get a spare battery.
But you can’t change batteries on the Hero+.
I would look for a Hero 3 White, its an older model, but you can probably find one cheap. Amazon or Currys have it for £150, including a spare battery. It should be good enough video quality for most things, and better battery life than some of the more expensive models. I think wifi is very useful for checking the camera is pointing in the right direction, and changing settings etc.