Hi Jenny
Firstly look at "uksorento.com" web site/ forum.
There are over 1500 Sorie owners, me included . More than 500 of us have fitted a German Power Box supplied by Taff Jones of Griffin Motor Tuning in Ireland together with a K & N performance air filter.
See Taff's site "www.griffinmotortuning.net
Tel No: 003536732935
Mobile : 00353868068581
Taff is a Welshman now running a successful engineering in Ireland.
You will see from the Sorento forum members just how fantastic the Powerbox is. The K&N filter furtehr improves BHP and Torque.
Mine is a pre face lift april 2005 model.
BHP is up from 140 to 167
Torque up from 343 Nm to 386NM
The car is more tractable, smoother and pulls much better. Fuel consumption has not changed very much but is marginally improved. It is great. Currently sells at Euros 365.00. A lot cheaper than the one you have ben offered. If you live near North Wiltshire I will gladly show you mine, so to speak!
Give Taff a call and I am sure he will tell you all about it.I have no knowledge of the DPT version.
Cheers
Alan