well...

CGI blocks are no longer available
custom steel crank from farndon £1300ish
i'd get the rods custom made with large small ends, probably arrow
custom pistons from CP, JE etc
there is no inlet available off the shelf, so custom
there is no exhaust manifold available really either, so custom
valves, springs, retainers, guides, stem seals, all from ferrea, around £600
ported ST head, from £500 to £1500 depending on who you go to
custom cams, kent, piper, cat cams?

for that power, nothing is easy!