Just a thought but would an A320 with extra fuel tanks do it. I gather Cyprus Airways has one for sale. Its probably a high cycle machine but you could probably customise the layout and interior to your spec and have it NOW.
Im not really a long haul fan but if i were to do it i think i would prefer to NOT have a bl**dy great yoke sitting in front of me for all that time.
As an aside do you currently go to any airports where ex-airliners are too big? i guess that could have some bearing on any decision making.
GW