Wait, do you already have the head installed at least? A brief rundown of that would be excellent, assuming the other parts are more just other things you want to bolt on before a dump session.
I have the N53 head installed, and (very) soon to be running on my car. Here is a brief rundown of what needs to be done to get this to work.
a) first and foremost, an N53 head needs to be sourced from Europe. Note that these weren't all that common to begin with...
b) several water jackets need to be welded shut and port-matched to an N54 HG, and the oil drainage holes need to be enlarged as well
c) head bolt holes are 1mm too small, and N54 head bolt washers are too large and need to be machined down
d) There is a 19mm hole/fitting in the back of the head that needs to be plugged
e) exhaust ports are completely incompatible with anything N54-related, so a suitable solution will need to be devised here
f) inlet ports have no drillings leading to the valve cover ports, so an external low-side PCV solution will need to be rigged up.
g) all other parts (intake manifold, cams, ledges, seals, valve cover, etc) fit with no modification
In all, it was a lot of work. And I don't think the effort is justified for anything but the most hardcore of builds, especially since most forum members here have head porting options available to them locally. Before you ask, I did not take any pics of the process above. I will however, share pics of my completed setup within the coming few days, in a separate build thread...
FWIW running an N52 head
properly would be the same deal, with the addition of the following
a) standalone ECU
b) milling the valvetronic bridge and fitting an intake cam ledge with some proper cams