VW T6 engines

[pete62]

Thinking of getting a T6 based camper van and have been looking at different options.
Regarding the available engines there are 102 , 150 and 204 ps options (both diesel and petrol in the top two) but are they all the same engine in different states of tune?
If they are is it worth paying the extra 3 k for the 204ps or buying the 150 and getting it remapped.
Anyone with any experience of driving the different ones and how they cope with the weight of the T6 or remapping them
Thanks
Pete