You can get the 1200kg payload in swb, lwb and lwb high roof versions, but unless you have especially long poles, they should fit in the standard swb.
Actually, both payloads will manage a 500l tank, but if you can, go for the bigger one.
Also, dont discount the fiat scudo and the peugeot expert, they are the same vans after all, made in the same factory. As has been mentioned, the 2.0 is the better engine. As well as being more reliable (and faster!), it is also more efficient than the 1.6, bonus!.
Citroen did a version called the xtr, which had higher ground clearance, mud & snow tyres and a fancy front diff/traction control system, which made it very good in slippery conditions. Not many about though.