Which garmin watch??

[skiezo]

My sone is a Mt bike guy. Michaux state forest abuts his back yard and he just put together his new Fugitive 138.
He wants a garmin watch and I personally have no experience with wearables that track and all that other stuff. He uses strava on his phone as a tracker but I think he wants to also track HR and whatever else these things do.
So, what watch in the garmin line would you recommend that is compadable with Iphones. Open to other brands also.
Thanks Brian