Undoubtedly this is an off the peg build the only question is, will it be Astutes or Virginia's. The decision might be something like 8 x Astutes or 6 x Virginias. Some sort of ratio like that, and a decision will need to be made.
Reactors will be shipped over complete. Never need to be refuelled, and will be shipped back for decommissioning.
That would be a very very sensible approach.