BuddyPress.org

@testador thanks for elaborating on what you’ve done so far.
– Check out the Ride Oregon site in BP.org showcase – https://buddypress.org/showcase/
– I recall seeing a travel or tourism site here before – http://www.bpinspire.com/

Re themes, I prefer to create my own themes – either child themes of bp-default theme or use BP Template Pack for a couple. It depends on a lot of factors. Here’s a simple walkthrough for BP Template Pack for reference – https://codex.buddypress.org/theme-development/bp-template-pack-walkthrough-level-easy-2/

Re media plugin, I’ve been using the BP Gallery plugin, (premium) since early 2010 to date. Preference is hosting own media rather than having it hosted at Kaltura/Cincopa servers.

Good luck