Now... go HD (Hi Density MD) if you're going to go MD at all... 1 gig of space on a disk... about 45 hours of music.. data transfers... easy uploads of recorded material to your PC.... (No stupid copyright feature)
http://www.sony.net/Products/Hi-MD/index.html
Make sure it has a USB port... Make sure it has both a mic in and a line in... make sure it has a back-lit remote...
I'm likely gonna be getting a Sony MZ-NH900 some time in the near-ish future to replace my old 707...