Standalone ECU for a diesel engine

[GoBe]

I can find reams and reams of information on after market ECUs for petrol engines but nothing besides x, y & z ECUs aren't suitable for diesel or direct petrol injection engines. Also initial enquiries with companies supplying ECUs are less than enthusiastic when they find the target engine is a diesel unit.

So does anyone have any advice or know where to start looking about engine management systems for diesel engines?