Koh Lanta or Koh Lipe?

I arrive in Krabi International Airport on Sunday 14th January. My original plan was to begin in Railay Beach, but I have done a bit more research into Railay and I'm getting the vibe that it can actually be a bit loud and busy.

I am deciding between Koh Lanta and Koh Lipe, as they both seem to offer the quiet and chilled vibe I am looking for.

What I am interested in is:

- Good beaches

- Good snorkelling (My understanding is that Koh Lipe wins here)

- Wellness centres/Yoga/Meditation activities

- Some degree of nightlife, without being a party island

- Walkable (my understanding is that Koh Lipe wins here also)

- Good Wifi Connection and Reception as I will be working remotely with video calls

Looking forward to your advice - thanks in advance!