A vintage bike can make a great commuter, but you'll have to make some compromises if you use a racing frame. I have commuted on two steel lugged racing bikes, a Merckx Corsa and a DeBernardi SL, and they worked fine with some modifications -- namely a large rear seatbag (Carradice Barley) and a good compact light system. However, both of these frames had barely enough clearance for larger tires and fenders, as well as no mounts for racks or fenders.

Eventually I ended up buying a Bob Jackson touring frame for commuting. It doesn't ride any better than my racing bikes, but is much more practical. I've mounted full fenders that stay on the bike at all times, as well as a front rack. Eventually I plan to add a rear rack, altho the Barley is sufficient for most of my commuting needs.

If you can find a vintage steel Japanese frame with mounts for racks and fenders, that would be ideal. Look for touring and sport touring frames made by Miyata, Panasonic, Univega, Bridgestone and Japanese bikes from the 1980s. Many of them had lots of braze-ons for fenders and racks, as well as clearance for larger tires.