hi mate i know u said u wanted a diesel engine but have u considered an evo 5-6 there 280hp standard
and my mate had an evo 5 that was 450hp after unwinding the turbo,air filter,dump valve and cams and now the car has been sold to warrinder who have spell £1 million on it and it runs at just over 900hp
now evo's u can tune to the eyeballs lol