Passion Ford?? This place has been passion BMW for ages
I had an e39 530d the open diff spoiled the car for me, I tuned mine to around 260bhp and it went well and the engine was good, the later m57n iirc was fitted with bigger turbo and maybe injectors.
performance wise the 335d would be the car to go for but apparently have a few common issues, give some seriously impressive figures after a map though