No. I use Jeg's brand nylon braided, or sometimes Evil Energy(Amazon Chinese stuff). I use the Jeg's for oil and the Chinese stuff for breather lines. No pressure on the breather stuff.
4 feet? That's not enough length to fret over the internal size of the fittings. I believe that only really matters if you route the lines up front to a cooler and back, then you're going 15-20 feet. 4 feet is not enough length for the "smaller" fittings to make much of a difference.
Having said that, both of the suction sides to my dry sump: case to pump, and tank feed to pressure stage feature AN-10 hoses and fittings. Both are bigger than 1/2" i.d. all the way through. All the pressure side and cooler hoses are AN-8.