If you use the '54 sender, it will come with a female inverted flare pipe coming out of it which will accept a flared hard fuel line.
I would recommend you buy the copper-nickle-iron (CU-NI-FE) hard line (you usually need to ask for it specifically). You can make most of the bends by hand. I used a bender for the really tight bends. Put the short flex line on the new line right after it clears the hole in the floor. You can either connect the other end of the flex line to an inline filter or directly to a hard line which goes to the fuel pump.
