Im doing the same conversion at the moment, bit further south though.
Iv got a touring too, to be fair an easier way of doing it is starting with a complete E34 540, therefore you have most of the things you need in an easy managable way and also you can sell the rest of the parts to make some of the money back. Even if you find a 530, you can mock everything up then drop a 4.0 in (plus they have the 5 speed box which is alot easier to work with!)
As said in many threads the difficult bits are the servo and manifolds, however if your handy it can be sorted. Most people run a servo behind the headlights which involves fabbing up a mount and lingage, however you can do this
http://www.driftworks.com/forum/drift-c ... biach.html
of which isnt mine but how I am running my set up.
Manifolds you hear things from allsorts of people, iv gone with X5 manifolds as they are a 4-1 collector so alot easier to start with and from a trial fitment I believe they fit without much of a headache, but I will keep you posted on that part!
Wiring is simple with a non ews car (M60B40) and is very simple if you have a manual box
Mounts - most people use e30.de ones
Again if you start with a doner 540 you can use the rad and brake set up from there, I am doing my conversion with Raw Motorsport speaclisits in race preparing and racing E30s and various other cars.
Just my little bit, and i know everyone has a different view on how to do it, everyone does the conversions differently so its worthwhile doing your homework before you start