id consider looking at modded engine bays in both colors too. depending on the finishes you want one engine bay paint color might set off the parts better.
I LOVE DSG .......white when done exactly right can be just as amazing too. choosing only one though, it'd be DSG for me. I've just seen enough of them to know id be totally happy with it. Not positive i would love the white as much. most of my driving is in the day as well so that plays a part
I have owned both, white is more of an eye catching color while the DSG is more stealthy and BA but you cant go wrong with either. I'd say go with whatever you find a better deal with.
I'm a big fan of metallic paint. It really adds POP to the look. All 3 of my SVT cars are metallic and I wouldn't have it any other way. White by itself is boring in my opinion, but when you add accents, it looks great too. A friend of mine had a plain white GT500 that looked like a pair of tighty-whitey underwear until he added all sorts of visual flair. It looks fantastic now.