So the Brock's won't work is that what you are telling me?
No it won't.
First you have to match the mounting bolt pattern to that of the Ninja 250, then the centers for the forks have to match. The Ninjas forks are really close and small (37 mm in dia. compared to 41 mm+ on bigger bikes). As far as performance parts for the Ninja 250, Brock's only makes an exhaust.
One of the main problems Ninja 250 racers encounter with their clip-ons and lowering the front end is handlebar clearance with the stock fairing. Often the have to alter the fairing to get the angle they want.