A strongpoint of the 767 vs the A330 is that it fits ICAO cat D gates that are present all over the world. Not conincidently I gave the Greenliner about the same wingspan as the 767.
The 787 and A330 have big lean wings to carry high loads & fuel over long distances efficiently but won't fit many gates and this might require many 767 oriented gates / airports to be adjusted..
B707-320, DC-8-62 and VC-10 have wingspans of 44...45 m. DC-10-10 and Tristar have 47,3 m, DC-10-30 and Tristar 500 have 50 m, A300 has under 45 m, Il-86 has 48 m, B767-200 has 47,6 m, A310 has 43,8 m, MD11 has 51,7 m and B767-400 has 51,8 m.
On the 2 aisles: you'll notcie it is still a narrowbody. The two aisles allow for pitches / seatwidth's in economy that would probably not be acceptable on 3-3 configurations.
As for what seat widths are acceptable on 3-3, have a look at Bring Another Engine 146 in 6 abreast.
and some realistic long haul premium options (I can't imagine efficient long haul First on a 757 sized aircraft).
What do you call what Eos has?
IMO for the passenger there is a win too, in terms of seatcomfort, handluggage allowance and more direct connections.
Compared to what?