With regard to brakes...for the little extra it costs i dont see why you wouldnt upgrade them. Locking up the wheels doesnt help you stop, bigger brakes spread the load better and yes decrease fade (agreed more necessary on track), otherwise why would other faster cars of similar size be running bigger brakes from the factory.
But its probably gonna workout the same way as the discussion ages ago about turbo vs supercharger...everyone will have their own opinion, to which they are allowed. 
I also stand by 4k being a decent, though high estimate on costs.
