as for recorders. i started out with dat, then moved on to a HD based recorder(jb3) and am now back fully to dat. with stealthing you have to factor in the analog to digital stage in your recorder. the dats being good and most of the hd based recorders out now (iriver, jb3 etc) arent great. im sure you will get alot of advice on this subject, but i would reccomend a nice dat deck (d100 or m1) if you have the cash. you also have to figure in level meters on the dats are far better than any of the hd recorders out yet.
i think those SP mics are definantly a good choice, but when looking at them you will be stuck with omnis forever. when i started i had a set of the at933s
http://www.soundprofessionals.com/cgi-bin/gold/category.cgi?category=110&item=SP-CMC-6&type=store that have the card/hyper/subcard/omni caps available. this might come in handy in stealthing different bands/venues. SP also sells seperatly a battery box for all thier mini mics that you can buy with a bass rolloff that is fairly decent for the money and the box is powered with one 9v battery
i really dont have any knowledge about any of the sonic studios dsm mics, so il let someone else chime in on those
you wont really need any battery packs. run a dat off internal AA's or a hd based recorder off of internal batterys. and the mics off of a battery box. i would stay away from using any stock mic preamps on any dats or hd based recorders