If they are to last that long, I hope they will all be bimodes to abolish "diesel under the wires". I hope in the next 40-45 years a large proportion of Northern's sphere of operation will be electrified including Settle-Carlisle, Cumbrian Coast and even Whitby but we must do better than electrifying 9 route miles/year for the last 5 years if we are to achieve this.That looks more like renting a train rather than for producing a new fleet.
A long-term contract would likely be reasonable here, as the trains Northern get may well operate for 40+ years.
I agree end gangways would be preferable for passengers but when did the railways last put passengers first?