I'm gonna go against the flow here and say push the geometry specs a little, just to see what you really can get. Less BB drop is always a good thing on a fixed gear. I've found that in practice, you never feel a higher BB, but never having to worry about pedal stikes is a huge bonus. Also, steep head angles and low trail numbers are GREAT for a fixed bike- your'e not gonna be bombing any downhills at 50mph and the quick steering is great.
Besides, if you decide you hate it, you have an excuse to build another frame!