Renault have made vans in Europe for years, and their Traffic vans proved popular with professional and DIY campervan converters. The vans were well-priced and easy to work with.
There are lots of professional conversions for sale, of varying ages. Some old bargains can be had if you have time and skills to do some repairs.
Renault's newer vans are popular all over Europe, and many are being turned into campervans.