Personally, I would have to recommend using an Aprilia hydraulic clutch. I just finished the install on my 72, and the operation feel over the cable is hands down better. I had the pit bike clutch from Ebay, and the longer line from HHB, but the combination of vibration, soft aluminum, and cheap o-ring seals led to leaks and failures that were unacceptable. I scrapped that configuration and began searching for an alternative. There are a couple posts describing the Aprilia clutch installation, and it was easier than I expected to get it to work.
Search ebay, as they come up for sale all the time. They can be a little spendy, as the components are Brembo, so it's up to you, but the extra money was well worth it IMHO. I'd be more than happy to provide pictures and help if you're interested in that path.