Generally speaking, I wouldn't ever recommend trying to burn a CD from a Zip drive. Way too slow, and you will have a shiny coaster (or mini-mirror frisby) maker instead of a CD-R drive. I'm not sure about the MiniDisc. If you can sustain a transfer rate equivalent to a CD drive then it might work ok most of the time. You mentioned you already knew the best solution in your question: hard drive.
If those multitrack recorders you named have CD-Rs drives they work with and have been tested and recommened by the manufacturers, then they SHOULD work resonably well. If you are just thinking about connecting these to your PC somehow to burn a disc, I would be very skeptical about the Zip.
