Since you did actually did some searching I will help you now. I discovered theres some better solutions to some things that were said in that post you found.
Things you need to fit the G240:
-The Getrag 240
-E36 325i 5-spd driveshaft with CB installed backwards
-E36 325i shift linkage will work and be centered
-Stock trans cross member THE M20 AND M42 ARE THE SAME! geeeze go look under your car!
-e36 transmission mounts (same as m42 so you already have those.
-Euro 323i throw-out bearing
-reuse your clutch slave cylinder as well.
This is all a 100 percent bolt-on affair.