I wouldnt go that far
T4 Transporters are great BUT everyone thinks so, so you will be paying scene tax unless you can keep refreshing gumtree autotrader friday ad etc .. and you might get lucky
Check out the different engine specs before rushing in, i had a tdi with a blue i on the badge, which mans its 88bhp sounds gutless but it was a great allrounder for me, my brother has a tdi it has a silver i on the badge and is 102 bhp and it really shows as it has alot of get up and go. These are both 2.5 5 cylinder engines, one thing to consider with the 2.5tdi model is the cambelt change it is NOT a home mechanic easy job and costs roughly £700ish if not alot more using proper Vw trained technicians.
Anyway there is SO much info on the above link you will become experts lol and reading the conversion threads you will be converting it into a weekend camper lol if you manage to buy one