I bought mine from "paylesstellfriends" on ebay.
eBay Motors: FIAT / ALFA ROMEO HEADLIGHT RELAYS , You'd be surprised at how much brighter the stock sealed beams get just by installing relays (at least on the GTV6). Nice clean voltage going to the headlamps rather than through all the oxidized connections in the steering column. I may swap to H4/H1's, but I just installed fogs under the bumper on another relay to help in those rural stretches... Daniel Stern Lighting has a couple of nice diagrams.
Relays: WHY AND HOW TO UPGRADE YOUR HEADLAMP CIRCUIT