TDRACER, I think the above concept shares the 2-3-2 with the 767 but would be composites panels technology like the A350, be lighter, less cargo capable (LD3-45) and range limited.
There isn't a suitable engine at this moment as you notice. However the market is much larger then the limited "757 replacement" Boeing uses to dismiss the A321LR. Evidenced by the 2000+ 757/762/A300/310s and 2300 A321s ordered so far..
I'm sure Boeing changes its mind when they have developed a solution themselves and I expect an engine will be there from GE, PW or RR to power it.
