i would stay well away from Hi Spec if I were you.....plenty of horror stories out there.
Stick to AP's / Alcon's / VWR, or have the brake god that is DaveB1970 sort out a custom set up for you.
Unfortunately the old adage of "if you want to play, you have to pay" is very true especially when it comes to proper brakes for use on track.
My R32 345mm set up will be ok for the odd track day here and day, and providing you dont hammer it too much and leave them to cool, but as Dave will say they can and will fade if abused! They're not designed for track use remember.