I haven't seen under the NC (or even in an engine bay ), or had a look at the auto box vs manual box but...
Have you considered if you'll need to modify the floorpan/tunnel to fit? Maybe, maybe not. Just throwing it out for consideration.
This is where you'll start to get into big bucks for it if you're getting someone else to do the work. Labour costs.
If you really want to do it though, good luck with it. Write a thread up when you're done, or a progress thread. I for one would be keen to read it.
Also you need to be a total masochist to do gearbox in/out jobs voluntarily.
Or really, really stupid. I've done a couple of engine/ gearbox swaps for free and I prefer to think of it as stupidity on my behalf, as my co-workers do.