The 6 speed box from a Touran is a direct bolt on replacement for my gearbox and will take my current clutch buddy. Which cost around £600. It's only 4 months old and not really done many miles, and should be fine (it obviously did a run or two while dripping oil out and didn't slip).
Sorry I should have clarified.
That's the only reason I am putting the 6 speed in otherwise I would replace with a normal 5.
The best upgrade would be the 2.0 TDI 6 speed as they are bolted and can take the abuse, but that's where you run into the clutch, driveshaft and starter motor problems - being that you need to swap everything out!