I've got a multiple choice question here.

I'm looking at flying from BKK to LAS in November and I've been looking at orbitz business class tickets which come to around $2200 R/T What I'm trying to fiugre out is which is the best transpacific airline to fly in business? It looks like the choices are EVA, China Air, Korean Air and Asiana which looks like these all go to SFO or LAX first. Any of these have lie flat sleepers in Business class?
Second part of the question is will my bags be checked all the way through from BKK even though there will be an airline switch in Korea or Taiwan?
Third part of the question is I'm wondering if I can clear customs in LAS via either SFO or LAX, or if I'll need to clear there, then shclep my luggage over to the domestic counter to check in for the flight that carries on to LAS.

Also will I get miles credited to my SQ account on any star alliance carrier even though this is a cheapie Business class ticket?