I have normal (not PTFE) -6AN braided stainless hose for my trans lines. Typical 37° aluminum fittings. Same lines have been on my car since 2003 I think. Same stuff I use for fuel lines. I have 3 cars done this way and have been that way for years w/ no issues.
The PTFE hose is better quality hose, more expensive, but not really necessary for this application IMO.

Steel lines are a real pain. The braided hose running along the frame rail makes life much easier.