Uber/taxi availability along Otres Beach guesthouses

Late August-early September will have 1 week in Sihanoukville and 2 weeks on Koh Rong - have not made the Sihanoukville city reservations yet as wondering if there are taxi services readily available, even at night, that would transport along Otres Beach and up to the town center. My husband has difficulty walking long distances and we would like to explore the various bars and shops but don't necessarily want to stay in the real touristy area so thinking staying a little south of town ( we are retired, traveling expats, not tourists on vacation) .. just wondering where we can stay for best walkable low-key dive bars to meet mix of expats, tourists, locals, maybe hear some good music, but making sure we can get taxis for longer distances. Thx for any suggestions!!