Your probably looking at something like a couple of years old Veloce group or older Centaur/Chorus (think 2001'ish). I get my stuff through eBay mostly, I can sometimes find stuff on Craigslist but have never wanted the full gruppo. There are a couple of dealers on eBay that sometimes have the older stuff, High on Bikes in the UK and Crosslake Sales, Ive gotten alot of disposable items from them (cassettes, chainrings) along with some FD and cranksets when they had them.

Some of the older Chorus and Centaur stuff you find in all alloy also but it probably won't be NOS.