Hi Thunder,
I've just completed Heathrow-Dubai in the 777-200ER. Apart from having an excess of 60K lbs of fuel on landing it went pretty well and I was pleased with my manual landing. I'm used to the 737-900 and Concorde.
I could do with finding a tutorial on those aircraft config files. The distance is 3100 miles and I used 60000lbs of fuel. Because of the excess on landing that should be closer to 50000lbs or so perhaps.
I've searched in vain for a decent fuel calculator. The only one I can find is that provided with the premium version of vRoute. If there aren't any others I may subscribe to them. I get many of my routes from them anyway and it's a way of repaying that service.