Upper Deck all the way on the 747, it gives you the small plane ambiance without the small plane bumpiness. Flown both planes, and the seat is the same. That leaves the cabin - single aisle or double is what I say it comes down to, the rest is essentially the same.
Also, FWIW, DFW is sitting almost in the middle of the width of the Country, and only an extra hour (less maybe) than LAX. I'd pick that if I were heading further to the East coast. Did BNE-LAX-JFK late last year, and the last leg being 5 hours. I'd have preferred it to be 2-3, so we'd go via DFW next time.