David, great news, please keep us informed with progress, what did the alloy manifold cost? as this seems to be a very sensible modification. i have heard of so many problems with the plastic one. (i hate plastics as they seem to have a mind of their own, the polymers leach out, they distort, become brittle and break)
The manifold was £50 delivered from VVC Steve aka MGF Heaven. Very reasonable I thought! It came with the injectors and fuel rail and the 2 little attachment doodahs (technical term).
Although I used my original injectors etc. as I didn't see any advantage in using the 135 ones.
It wasn't a difficult job apart from the studs/bolts thing. Luckily I had some bolts of the right size/hardness already. The alloy manifold uses an additional two fixings so I reused two of the studs in the additional holes and used the original nuts on them.
You can see one of the additional fixings in this picture (above the obvious ones)