Ok, so if the blocks got to come out for machining, it's it worth doing for just the bottom end. The overall plan is new everything, but the main items being
Heads & cam
Intake
My original plan was to do the whole lot and take my time over it (with a spare engine in the car thoughout the build). Is a 3+ staggered approach (i.e. Bottom end, Top end, intake) viable/better bet?