whats you exhaust housing A/R size? the front looks like 80 which is quite big but both can be easily changed over if required to another picked up cheap from silvia forums or other SR and CA engined based forums.
Contact Clyons8 for a turbo manifold also look for a cheap stromberg 1.75 or SU.
Nicks old A14 should have kept it and developed it further woudld have gone better than most ca18det :)
http://www.youtube.com/watch?v=3Rxd6-i10_k