I believe that only CETME model A used the odd 7.62 cartridge (shortly before NATO standardized 7.62), with the later models using standard 7.62 NATO loads. All of the "new" CETMEs on the market use standard 7.62.
It's easier, and less expensive, to put together a FAL than it is a CETME or HK-91 clone.
The only parts I had to pay a gunsmith to do on my FAL were to barrel/headspace and braze the muzzle brake in place. Everything else I could accomplish in a few minutes with a screwdriver or no tools (fire control parts). There are a lot of FAL competent smiths out there, and if push came to shove, you could do it yourself with a receiver wrench being your only special tool. I've paid as little as $7 per mag.
On my HK clone, I had to pay a smith to do all of the above plus clip and pin the gripframe and modify the fire control parts to semi-only. There don't seem to be as many HK competent smiths out there and those that are truly competent are pretty expensive. New or even just decent used barrels are hard to come by. The least I've paid for a mag is $20.