If your BB cups are at all worn, you may want to consider concurrently upgraded to a cartridge BB while getting a shorter spindle. Decent Shimano BB's can be had for <$25 from your LBS, with the added benefit that they'll likely accept an exchange if you get one a little too short.
Also, if you do get one that's too short on the drive side and seems like it could come in a bit on the nondrive side, BB spacers are dirt cheap and come in 1 or 2 mm sizes to really dial in your chainline. Before you get a shorter spindle, double check the amount of clearance between the chainrings and the chainstay.