Nice one there, looks like a fairly clean van. Got a set of minus 40mm springs kicking around the garage if you want to drop it a bit. Was too low on mine 'cos I've got the body kit as well but on a stock van, they'd be fine and greatly reduce the body roll on corners.
By the way, it's actually a T5 Transporter, the 28 is the spring rating i.e.
2800kg ... ok ok, so I'm a VW van nerd

I admit it.
Check out
VWT4Forum.co.uk for some ideas. There are some good ideas out there for multi-purpose vans without going the full conversion route.
For instance, how about a
Kombi bed. Still get the use of the back seats and storage in the back.