Which Groupset?

But BBs are incredibly cheap, and external ones don't suffer from the myriad problems associated with square taper cranks. If you have to replace you BB every year, so what? It's quick, easy and cheap.

I've never had any problems with square taper cranks in the past. On every other bike (except the vintage ones) I'd agree that external BBs are superior. But this is for the winter bike. Maintenance is supposed to be limited to scraping the crud off once it gets deep enough to plow.

And replacing Campag Veloce BBs is a massive PITA due to the massive PITA which are PowerTorque cranks.