Chains are not expensive. Buy a chain like the sram pc-58, it will be fine with the veloce triple. I would suggest going with a bottom bracket with a 111mm spindle length. Here's Sheldon's page on chainline:

http://www.sheldonbrown.com/chainline.html

Where you may run into a problem is the front derailleur. I'm not familiar with the PX60, but being French, it may have a seattube diameter .6mm smaller than a standard seattube. This will make finding a triple compatible front derailleur a bit more of a challenge. Shimming is one option that may or may not work for you.