Shimano and Campagnolo make the best cables and housing. By far.

Do not buy the overpriced 'kits', which cost multiples of what you should pay for housing pulled off of a roll. We charge $2 a foot for housing. $2 per cable.

Do not buy stainless cables. Stainless strands have less flexibility than regular steel, resulting in more cable breakage, particularly inside the tight confines of shifters. Why would you need a high resistance to corrosion, when the cables are protected inside the housing? I suppose a rain commuter bike might warrant stainless.

Make sure that when you cut the shifter housing, that the ends are filed flat and clean.