306 van?

[ozonehostile]

Basically, I'm going out as self employed in the new year as a welder/fabricator/engineer so will be looking to get a van of sorts. 

I don't need anything too big as the most I'll be carrying will be a toolbox or two, an inverter mig welder and gas bottle. 

My thoughts are that the hdi I currently have would be perfect, reliable, economic, good performance etc and you can fit a fair amount in a 306 with the rear seats removed. 

On to the subject of vans, I know the 306 van was pretty popular over in Ireland but just looking for information on the rear load bed/bulkhead and the rear window blanks. 
Are they removable fixed in the standard glass mounts? 

What's the deal with declaring a car as a commercial vehicle? I know that a Landrover with plated up rear windows can be reclassed as a van, just a case of writing to the dvla? 

Any thoughts welcome.