M60 gearbox!

[4002H]

i have a e34 540 (m60) with a dead auto box, the engine is all good lots of history and i no it had the cylinders re lined by bmw!! my question is that i need a manual box to go with this engine, the factory fitted 5/6 speeds are almost impossiable to come by in the UK plus when they do come about (iv not found one in almost a year of lookin) the breakers are askin for as much 3000 pounds (almost 5000 USD).

dose anyone no if you can use a box from a 6cylider? im not worried about props or anythin i can sort that easy, and or mounts, i just want to find a manual box that we'll work with my v8!!

any clues would be welcome and sorry if this question has be asked iv spent hours searchin many thanx