Motul RBF600 brake fluid FTW. And SS brake lines are always good. Get the Z1 non-premium lines even if you have the sport brakes. They get rid of those stupid banjo bolts, which are just another potential leak point.
If the shuddering is while braking hard at speed it is likely uneven pad deposits on the rotors (also commonly and incorrectly referred to as "warped rotors"). If this is, in fact, the culprit then you can either replace them or have a shop "turn" the rotors. Basically they scrape the rotor to even the face - note that bad braking habits will cause the problem to return. Avoid sitting on the brakes after a hard braking session; put the car in N once you come to a stop and stay off the brake pedal if safe to do so.