I have seen two methods of installing a kombi box,
The first is the custom offroad kit. It puts the nose cone through the stock hole in the pan. No shifter adaptor needed. Because of this the gearbox sits with the front down low and the back up higher, so the engine and box is on a slight incline.
http://www.customoffroad.com.au/kombibox/Kombi%20Box.htm
The second method is the Sharpbuilt method. it puts the nose cone through the lift kit. you use two couplings welded on top of each other to adaptor the shifter. I decided to go with Mike's kit because I liked where it made the engine and gearbox sit, basically flat and high.
You can see quite a few pics on my website through the rebuild and V6 diary's.
The sharpbuilt adaptors are design to use the stock beetle mounts. You can see it in this pic
and the coupler is here
The coupler through the lift kit can be seen here