I skipped all the UN-73 talk
It was good stuff, just stay away from the french and dutch and belgium
If you are looking to build a SS, the existing 27 inch wheels will take you thru much
However, if you ever want to build a Fixie, my opinion is that you should start with a 700c bike. Life will be easier, less costly, parts readily available on CL or ebay, or at swaps.
The note on forged vs stamped drop outs was very good. To me stamped drop out = not much of a bike even when new