To be fair, all we know at this stage is five car, diesel and a max speed of 125mph. Every manufacturer could build that.
I am not sure whether any are diesel. There are 12 EMUs (60 carriages) in service by end of 2019 on Anglo-Scottish routes and 19 bi-modes (95 carriages) to be introduced on services via Newcastle by end of 2020.
New trains start to enter service by end of 2017 to enable additional services to Edinburgh, Hull and Scarborough.