Here's a link to the 128i's (N51) intake manifold: http://realoem.com/bmw/showparts.do?...56&hg=11&fg=40
It has a part number of: 11617559523
The 125i according to realoem has a manifold part number of: 11617559523
That's a positive sign. The N51 has slightly lower compression than the US N52N but it does have the 3 stage intake and a couple of additional catalytic converters... that's about all I know.
Ordered: 128i Titanium Silver, Black Leatherette, High gloss black trim, Sport Package, iPod Adapter, Premium Audio, BMW Assist