I think MiniDisk is the technology of about five years ago. The comparable thing today would be the portable handheld recorders that save to CF or SD cards made by Tascam, Edirol, Zoom, Sony, our old friend Olympus, and at the high end Nagra. These usually have stereo condenser mics, and the better ones can accept external mics.
I haven't sorted out the whole sound business myself. I picked up a couple of Nagra SNSTs absurdly cheaply from a government surplus auction on eBay, sold one to a collector for about forty-five times what I paid for it, and kept the other one. I've seen Pilotone setups with these, but I think it's going to take a lot of waiting and hunting to accumulate all the bits and pieces, so meanwhile I use it to record lectures and such (it's really a fantastic speech recorder), but if I don't have everything together when I'm finally ready to try sound, I'll probably sell it and get a portable digital recorder.