I tend to go down the Y,B,L route.
London to WestCoast USA I tend to pay around £750 (fare+taxes and fees).
You will pay the UC fuel surcharge as part of your fare.
As to what is best for you, i think it depends on how highly you value a flying club mile. When calcutlating remember your Y,B,L ticket will earn economy mileage + status bonus, so the true cost is less than 60k miles, for the west coast you earn a minimum of ~10K miles + status miles + tier points (if you need them).