For my Falcon Merckx, I found a 130mm Ultegra rear hub, respaced it to 126, had a friend lace it up and I'm running a full 9-speed cassette.
If you want to go with the 8 of 9 on 7, like Sheldon suggests, I have the setup for you. I got this before I decided to go full 9-speed. It's an older NOS Uniglide hub for which I have the Hyperglide freehub and correct dust cap but personally I would just suggest you go full 9-speed.