I guess you have been speaking with Frazer? I've been helping/working on his drift car the last 9 months and have some advise regarding the clutch kit/gearbox.
The short answer is, don't bother with this conversion if you are planning for this to be a daily drive or a comfortable cruiser.
The clutch kit and BMW box feels very racecar like, in the sense that the clutch is hard to use, the clutch is very noisy etc. It's saving grace is that it's relatively cheap in comparison to the 6 speed, and it can take a lot of abuse for what it is, and worse comes to worse a new gearbox will set you back a few hundred at maximum.
Installation of the kit is incredibly straight forward and the quality of the components used on the clutch kit are high.
In my opinion, if I had a drag/drift car that I wanted to build but couldn't fork out for a 6 speed getrag, then this would be the next best thing. Using this kit on a daily/road basis is interesting at first, but quickly becomes tiresome.