1) I recently upgraded to a set of UUC SS brake lines. The fit, finish, and quality were all top notch.
2) They are covered in teflon because SS will pretty much saw thru anything it comes in contact with. It also keeps dirt out of the SS braiding -- which will destroy the SS braiding.
The only real reason to 'upgrade' to SS brake lines is to keep them from being severed. They do NOT increase pedal effort. Many people say they do -- this is a placebo effect. Call up UUC, Stoptech, Goodyear or whoever you want and specificaly ask them how they affect pedal effort. Unless they're lieing out their ass, they'll tell you they do not change the pedal effort.
Stock rubber lines are very good, especially on your car which is just a few years old. The rubber lines actually have an inner coating that will not really expand much under pressure. It may a little bit, but not as bad as many people try to say they do.
In short... I upgraded to SS brake lines just because I could when I replaced my pads/fluid/suspension. After 10 years, I'm sure my rubber lines were not as good as when they were brand new.
The UUC lines are very well made. If they make them for your car, I would get them. If not, try Stoptech and Goodyear. Does Dinan make a set?