In response to GirlAnachronism, you're right that I'm worrying too much about certain details, but the quietness of fixed gears is one of the main reasons I want to build one. So I want to get the right components before I find out that I've wasted $50 on a chain, or even worse $150 on a 1/8" drivetrain.
I'm not experienced enough to give you advice, but don't ever apologize for wanting things right. There's nothing worse than spending a lot of time and money to get a new toy, and have some annoying defect that ruins the fun. I had a similar issue with my chainline/noise, and I spent the time with my LBS to sort it out completely. The bike runs ninja-silent now, and I'm
deleriously happy with the results.