agree with roy - tune is as important as a good build.
i would say that anyone who has the right specs for the torque values, and all machining is done right, can assemble a motor well. Hell, I reckon with the right tools and enough time I could put together a motor that will hold together perfectly well. It's things like custom oil control, sump mods etc that I
don't know how to do, nor know exactly what to do... that's what you're paying for.
then a nice conservative tune with not too much heat (as roy has said), tuned for mid range power, will see you happy for a long time. mine has 2680s on it and makes around 340rwkw on a stock motor and drives great - on the street i don't need anything over 6000rpm.