I'd say red... because I don't like yellow... unless your car's red... or yellow... then I'd pick neither or you'll look like a Mc40
However... the only performance impact it really might have is on the ladies... but probably not... they're better with colors anyway so I'd ask them
The drilled and slotted question is a good one... but a better one is what do you want to use the car for first off?
There is a good chance a standard Z32 setup with an excellent pad will do very well for you... for most people I'd recommend plain (due to pad life being reduced with a slot setup)... but here's a good ref article from the company who makes my brakes:
http://www.stoptech.com/tech_info/faqs.shtml#15
I have slotted (mine is currently a track car/street car with a bias toward track since it's not a DD ) due to the vary reason there is a warning about drilled in this article. You are introducing a lot of localized stress concentrations with holes... just isn't smart if you ask me