You replaced the entire master cylinder, then? If you're still getting fresh fluid inside the cabin above the pedal, it could be that the unit you got was defective, imo. Inside the cabin is a sign of the master failing. It happened to me and I bought the rebuild kit from Napa for about $30.

If nothing else, you should get under there and clean the area thoroughly so you can check it daily to see if that is, in fact, where it is leaking from this time around.

As for the stainless line, you can buy it from RRE for $20. I can't say how hard it is to install, as mine has been hanging in a bag in the garage for a couple months now, easily. Shouldn't be too hard to do.

Just be sure you troubleshoot the problem down until you are certain what is wrong with your car before you go buying all kinds of parts. Save yourself time and money!