Contract Pilot
The 650's can true out @ 460 kts and routinely cruise at FL's 410 and 430 if ISA temps are good and cool.
They can fly for about 4 hr + 15 and then you need to start down and land. This landing fuel load is 1500 lbs and needs to be increased for night or IFR app's.
So you will be flying the spruce gooose routes to EU or the wet foot print to the Azores and the Pacific is arc way north.