Best I could find that works for me is LAX <-> LAS in United Buisness first on a day when I will be in Los Angeles. £164 Departs 06:35 and I'm back in Los Angels at 10:33. Worth thinking about although I was hoping to avoid doing a mileage run.

LAX -- SAN was very expensive. SBP (San Luis Obisbo) is economy only.

LAX -- SFO was £186 and the flight is longer. On the other hand I might enjoy spending a day in SFO.