recommendation for slide copying

What sort of carrier/stage do you use for 120 film? I have 6x7 color negs that I'd like to shoot. I have 5D2 with Canon 50/2.5 macro, 100L IS, Leica 60/2.8 macro and Leica 100/4 macro -- I'm sure at least one of these would work, if I can find the right carrier and illumination.