Good morning
I'm the UK A2 owner who has this conversion finished.
I've gone for
BCB Block
AUB rocker cover with cams
AVY inlet manifold, injectors and throttle body
AVY exhaust manifold
AUA gearbox
AUA flywheel because its lighter so revs faster
AUB ECU
Larger diameter ignition leads, backbox delete and a cold air feed induction kit
Very happy with the results, no wiring mods needed except for the connectors on the injectors.