Well the color is purely subjective, so you're just going to get everyone's favorite. I'd say the color that makes your heart skip a beat when you see it on the car is the one you need to buy. I have the red metallic. It looks fantastic in the sun.
Probably the only parts your dealer will install are the Ford Racing. If they do install any other brands they surely won't be warrantied through Ford. FR parts are warrantied through Ford. I have the track pack on my car because I plan to do some HPDE's with it. 95% of the time though it is my DD. I think the pack is worth it for that reason. If you never plan to track it, I'm not so sure you'd benefit from it on the street. I suppose some back road running would be more fun. You'll just have to deicde if it's worth it. It's not like running a back road is timed, so you'll have just as much fun without the track pack. I don't really find it is bothersome on the road, it's just the money factor.
I purchased an axle back FR GT500 exhaust. I really just wanted the extra sound, not performance. So I went cheap, only $300 to my door. Again, that is all preferrence.
Good luck with your search.
13 Ford Mustang GT Track Pack 6MT (my DD)
06 BMW Z4M Roadster (weekends)
97 BMW M3 (Race Car)
99 BMW Z3M Coupe (back-up race car)
85 BMW M635CSI (Show)
10 Subaru Outback 3.6 (wifeys DD)
08 Chevy Duramax 4WD (tow)