If you don't need bass roll off in your battery box, get this one from Chris Church:
http://cgi.ebay.ca/STEREO-MICROPHONE-BATTERY-BOX-4-MINIDISC-MD-MP3-EDIROL_W0QQitemZ5861399837QQihZ016QQcategoryZ3281QQcmdZViewItemYou do need to supply your own 1/8 male to 1/8 male output cable. I use the Headroom 4 inch mini to mini that you can get here:
http://www.headphone.com/products/cables-and-adaptors/interconnects/The package is more expensive than some alternatives,
but it is so small-I velcro the box to the back of the recorder a
nd there is no excess cord to get in the way. Also, unlike other small boxes, t
he Church uses a regular 9 volt battery that lasts hundreds of hours.
The recorder & box fit in my shirt pocket, so I can see the levels. I cut a hole in the pocket for the mic cord and hide the mics in my hat. I've gotten incredible recording with this combo plus the MM-HLSC-1 cardioids into line in. It sounds great with the HI-SP mode (almost 8 hours) as well, when you don't want to change discs. I can't hear the difference. Absolutely incredible for stealth-easy to get into the venu & nobody can tell I'm recording.
The mic input of the MZ-RH1 is supposed to be excellent also, but if you have to turn the levels below 11 (or is it 10?), you will brickwall, so it would be dangerous not to use a battery box into line in for a fairly loud show.