Careful work with a hand drill will do it. And brake line can be used.... plenty of fitting from inverted flare to NPT. I'd put a 1-2" loop in brake line to give some expansion room.
Yes, those 45 degree fitting look problematic. but the whole deal looks nicely done!
Do you have any provision for adjusting a restriction to control the flow? Perhaps a straight tapped holed behind the angle fitting in the head, to put a changeable restriction? I am imagining a Holley jet for flow control! (Brass in aluminum is not a good idea unless you can keep all water away... which seems the case here.)