As the title says....does anyone know if there is a company somewhere in Europe that sells high roof (fiberglass) for Sprinter 2001-2006?
sprinters sold in the UK had the option of various roof heights from the factory, and so I would be suprised if anyone sold aftermarket conversions. Most of the roofs will be available from scrap yards now but they did sprinters in various wheelbases so you need to specifiy the length when enquiring.
Mercedes 1823 4x2
ex brinks cash-in-transit truck
The only aftermarket higher-than-normal roof I ever saw on a Sprinter van was from Westfalia, but they only sell complete new units. Otherwise, RV manufacturers just start with the chassis cab version.
It's better to regret the things you've done, than the things you haven't.
May be you could have a look at Reimo, german RV component supplier :