My advice wait for the new model if buying new.Its payload will be between 1000kg and 1200 kg with more space inside.
If you are going to buy now ABS brakes are not fitted as standard on the 1.9D engine. They are a must in my opinion, they could save your life and make you van far safer,That alone is more important then any speed you will gain with the Hdi engine. But do you want to be flying around that fast with a full load on.
If you are only putting a 400ltr tank have you considerd the Doblo van, The 1.3D multijet engine is an absoulte cracker. Take one for a test drive you will like it.
Nel.