SS lines are fine depending what type you get. try to get some lines that have a rubber coating on the outside of them if you are worried about them rubbing.
komodo, the point of them is that they stiffen up the brake pedal a bit more. not much, but a bit. they also will not swell. personally, as my car is being driven around the track the brakes will fade and since i do not heal/toe like most people, the brake pedal will be moved closer to the floor while my gas pedal is the same and i will be over rev matching. hopefully, along with stronger pads/rotors, the idea is to eliminate this feeling. SS lines are just another part that helps.