Buy 79s brakes, the XV came with larger rotors versus the non XV Imprezas, cursory inspection shows they are identical to early WRX and current Forester.
That being said, I felt a huge improvement switching to stop tech pads and synthetic brake fluid on my 2012 Sport Limited.
Plus I will still have the option to go down to 15" wheels and ultra inexpensive snow tire options in the future. The XV, Forester, WRX upgrades require 16" or larger.
As for SS lines, unless you are doing track duty or autocross, they're a bit of overkill.