There ain't such no thing as a low loss thin cable! not for high
frequencies, anyway! what experience teaches is to put up the thickest
line you can within the closest reach of the antenna, and use the
absolute minimum of thin, flexible cable from there to the antenna
itself. in any case you need good connectors at these frequencies so
the additional price is not a real killer.
there's no way to dodge the physics at these frequencies. try to fish
out reel ends of CATV cables from your local comapny. usually they're
glad to give it away, if you rid them from it. I even got e afew
connectors for my pain. in any case you need to match the antenna to
the cable, so why not at 75 ohms instead of 50?
Saandy 4Z5KS