Matthew,
A number of options I would pick again without question:-
Dual battery system
Sun roof
Air suspension
Centre & rear Diff locks
Suitable rim size, 17 inch max, mayby 18
Saltlake grey, or any grey colour
However, at the end of the day, any option is an individual thing, but each has it's purpose especially when travelling.
I am happy to assist in providing a detailed reason for each.
As for towing, the V6 TDi I am sure will do the job well, however when I looked at the R5 and compared it to the V10, they were miles apart in every respect, especially towing, their comfort and ability.
Sorry, but I just don't like the look of the Porsche V6 or not.
Regards
Gerald