I really don't see any reason why stainless steel brake lines would cause your brakes to make noise. One of the easiest solutions is to use anti squeal pastes. Available from Autozone. I believe that BMW is also supposed to use it when replacing brake pads. Part number 81 22 9 407 103.
2011 E92 M3 DCT
1991 Spec Miata
2008 E92 M3 DCT - KW Competition 2-way / Brembo 365 BBK / OMP ARS racing seats / rear seats delete / GT4 aero / AiM EVO4 data logger / SmartyCam racing camera
2008 E92 M3 6MT
2008 E92 335xi