You're not overthinking it if you are worried about a one-of-a-kind bike. The saying is "don't race what you can't afford to replace" and I would consider a unique paint job to qualify. On the other hand, trying to find an unpainted frame might be a bit extreme. There are a number of great options, especially in alloy: Specialized Allez, Cannondale CAAD 12, Trek Emonda ALR. You could build it up with 105, get a decent set of wheels and tires, and you've got a solid race bike that won't break the bank.