I use the Cinelli Spinacci bars; not quite full aero bars but UCI legal.
New they cost $99 about 10 years ago; if you're lucky you can pick up a used pair for a couple bucks at a bike swap meet.
I actually cut them down a bit (with a hacksaw) to suit my riding style. It's nice to have a bit stretched out position and don't really do it to be aero.
Pedal on!
Rudy/zonatandem