In reply to Jus:
What type of van are you having converted.
I work a little with the VW scene and could tell you some of the better and worse converters.
Also you will gain invaluable info on the t4forum with regards most things inc conversion companies.
Hope you enjoy it when finally take delivery.
Oh and why will it take 6 weeks for the top and bed to be delivered? I know these are readily available in the uk and the only thing you should be waiting for is colour matching if your having it sprayed.
I would be worried with the company you are using if they are telling you there is a wait on roofs and beds. Most companies that are good will have a wait to get the work done and it should take upto 6 weeks to do a full conversion.. But not just to get you the products.
Drop me a pm if you want any further advice.
Tony