What style fuel line is best?

Follow the factory. Hard line except where soft line connections are needed.
Stainless if heat and rust are a concern
3/8 if it makes you sleep better.
Make sure the filter outlet is higher than the inlet - just like the factory.
Final stretch to the carb depends on the carb.
Braided stainless with real AN fittings are generlaly trouble free and will let you take the bowls off a holley a little easier when messing with the jetting or blocks.
A fuel log is nice if using a return line and pressure reg on the return.
I prefer steel hard line for the Holleys with a hose between the front and rear bowls.
But quality on most off the shelf is so-so.
If you're racing, look in the inlet and see if the connection is restricted. If so open it up.
The aluminum versions look nice but some (many?) have braided held with hose clamps.
Aluminum transfer s heat into the fuel quicker and if using hose clamps, might as well just make your feed line own out of a cheap steel one.

PS. insulated firesleeve and reflective fibre glass sleeves and wrapping over all my fuel lines in the engine compartment. And where the headers are super tight tight, zircotec's foil is the first line of defence. (it won't melt or burn if it touches the header.)