where to buy? New stainless fuel and brake lines

Fine Lines in Ohio has pre-bent for a great fit. You did not mention what car you are doing. They have ones for AMX's I don't know if they have ones for later amx's

Fine lines does not always fit "fine" Inline has the best fit. It's all we use now

I bought every line for my 70 AMX from Inline in 2016. NONE of them fit. None were labeled, just thrown into a big box rattling around. Many calls and no customer service. I had to stop payment on my card to get their attention. I had to arbitrate through my card company to get my money back.  Cost me $60 shipping.

I bought through American Parts Depot for my 70 Javelin and I can't recall which of the line producers they resell through their site (they were drop-shipped from one of the two, either fine or inline, but they didn't fit worth a #$@#@ I had to rebend, they didn't seal well, one was too long and I had to get creative to bend it to fit taking up the extra length...........
Never again will I use stainless-  I use nickel/copper now. FAR easier to work with, seals easily.
Stainless is a lot harder to get double-flared and sealed well - takes a heck of a lot of torque on those little nuts. 
I did all of the lines on my 73 myself using a roll of the new/modern nickel/copper and zero troubles. 
The cost for my 70 was crazy for the quality I got. 
I also figure that if a person takes care of the cars and does the flush every couple of years, and so on - since the originals lasted 40 years (and they really weren't shot), pretty much anything I use will last longer than _I_ do!