I don't see the petrol versions revving to 8,000 rpm therefore I suspect there's little in it standard to standard? Remap the diesel and as much as it pains me to say it I'd expect it to leave the petrol wanting.
Say what now? Never thought I'd hear you say something like that...
I dont want to sound like I'm talking down to you, but you seem to be placing a lot of importance in the extra economy of the diesel versions, but given what you've posted previously about your approach to acquiring a workhorse, have you actually done the numbers properly?
How many miles are you going to be doing? Do you have a fuel card?