I'd go for Hi-MD instead of regular MiniDisk. With Hi-MD, you can record in linear PCM, lossless audio. In addition, you can do a direct USB transfer to PC, so you won't need a CD recorder or home MD player to do a transfer. Make sure you get the remote as well. I'd suggest the Sony 900 or NH-1, I'm very happy with my NH-1.
Check out
http://www.minidisco.com/ for more info. Be sure to search eBay as well as Google to get the best deal.
Check out Sound Profesionals for mics
http://www.soundprofessionals.com/ Good prices & quality, & the customer service can't be beat.
In addition, they offer TS.com members a 10% discount off "their" items (with a stock # beginning with SP- ) -->
http://taperssection.com/index.php?topic=23681.0Be sure to search & read here at TS. There is a wealth of info available. FWIW, I've heard nothing but good things about SP mics, from the less costly to the most expensive. I use SP mics, & I'm happy with them.
As far as the battery box, you can get the levels or bass roll-off options, or just go for the basic model. I just have the very basic SP-SPSB-6. I'd suggest getting one of the full size 9v models, not the mini battery type. You never know when you'll need to grab a battery when yours dies (& you forgot a backup). Things happen, & you can grab a 9v at almost any convenience store--not true of the mini batteries.
Let your ears (& budget
) be your guide.
Good luck, & +T for taking the plunge into taping.