The airbag delete was easy just ordered resistors off Ebay, I haven't got around to sorting out the heating wiring just yet. They are so comfortable, great seats, good choice! Sent from my SM-G950F using Tapatalk
You might want to try a test sit before buying extra seats for your Transporter - the seating position is way higher so the Golf seats might be uncomfortable when sitting in a more upright position.
As far as being slow VW did offer a GTI engine and 4motion AWD for the Transporter (unfortunately not in Oz), with an ECU tune (and not too much weight on board) I'd imagine it would be quite a surprise packet for a van