Well that would work out, as from what i have heard is that the lease for the 743 is due to end mid November this year and i have not heard of any plans to extend this lease again.
As for the 767's thier longhaul economy cabin is 2-4-2 with 32" legroom. The XL one cabin is 2-2-2 with upto 45" legroom. As for the premium economy section i am not sure if they still offer this service but when they did it aws 2-3-2 with upto 35" legroom.