You'll not be disappointed by either , I'm sure, but if you get a T4 check the pedal box for clutch pedalbox fatigue. A known problem that can be cured by"windwelder" on T4 Forum. A pain if not rectified. Speaking from experience! Cheers for the RFX jeans back along. Done well.
I have a 2003 T4 and love it big bonus with mine is it is a factory Kombi so it is registered as a car i know of a few mates that have fitted windows and seats in vans and are having to pay a lot on insurance as they are now modified . I believe you can reregister them as long as you pay for a dvla inspection . Good luck with your search the T4 are fetching strong money at the moment you can probably get a T5 cheaper