Originally Posted by europa

Buy the bottom bracket that comes with the crankset.

For the headset, take your frame to your lbs and buy what fits. They all have a stock of the things on hand. My experience has been that they'll press the things in for you while you wait and this saves mucking about getting special tools. I've never had to pay for it either though I've only ever used shops that know me well because of all the other stuff I buy from them.

Chain? I'd normally suggest going to the lbs too, but you might find you can't get anything heavier than the SRAAM PC1. The PC1 is an okay chain but you can get longer lasting chains such as the Miche Pista (from my personal experience, a very good chain) or the KMC K710 (often recommended, I have one but only with a few hundred kms on it) - much heavier duty chains. Your local track shop should be able to help with them though if you're ordering bits from a supplier and they sell chains as well, why not include a chain?