I'm going to use black hose and an fittings. I was thinking 4 an for the hose. Are the fittings in the turbo and the block coming out of the motor both 1/4 npt?
Unless you are planning on strategically mounting the "hose" so that it does not come into contact with anything...scratch that. I think that's just a bad idea. Get one of those pre-made brake lines for a few bucks at the local parts store and just bend it with your hands to make your own. Can't remember what length, but it's one of the standard lengths and it will already have the NPT nuts on the end.