The M10 is very well thought of around here, but it does not do 4-channels. Some of the Tascams go up to four channels, good units as well.
If you run the pre-amp you do not need the battery box. The Church audio amps supply the correct power for the mics he sells. As a note be sure to turn the plug in power off on the recorder if using the pre-amp.
Be sure to check the church audio threads, on occasion he runs really sweet deals on complete packages. The last one I saw was for the CAFS which are super tiny, like the size of a pencil eraser. For ease of starting, a church rig comes ready to go, and there is substantial info on the board to get it running. I have run my church gear in so many ways, stealth, open, cards, omnis, even 4-channel card/omni combo.
I will caution, and most can attest, no matter what you start with if you enjoy the process you will have a ton of shit in no time. Six pairs of mics, three pre-amps, clamps stands, cables.........