New Vans are just like everything else in life, you really want it but don't really need it.
Thanks to consumerism our minds our wired to want the latest and greatest, yet we never really feel truly satisfied.
The novelty will wear off in a year or 2 and that ugly monster consumerism will force you to start thinking about the next best thing, tying you down into an ever lasting cycle of payments and interest.
Don't let desire get the better of you daz, or before long you'll find your working for the banks and not yourself.
One thing that has always struck me is how humble you've seemed ( ok with the odd bit of boasting on 5* holidays ) and how you've always been so proud of your setup. Even though you were driving an older van and didn't have the greatest professionally fitted wfp system on earth, you are always happy.
Now your burdened with long term payments for a van that's not even yours, that will lose a large chunk of its value within the first year, when in truth you could of been a bit more clever and got a good van without all the aggro.
2 years ago I bought a 13 plate dispatch L2 model, around 20,000 on the clock for 7k cash, no vat. I searched the whole country and drove 200 miles to pick it up. It was practically a new van still, and its mine outright with no payments or interest. Absolute bargain.
I didn't even consider spending a fortune on a super duper, gold plated parts per trillion, diamond encrusted system. Why would I, it does the same job as every other system that you can put together for a couple of hundred.
In all honesty dazmond, chuck your old 500 litre system into your new van and spend your money on life, not on a new system.
Over the next 5 years put away £30 a week and buy your next van outright for 7k.