Sony M10 (if you can find one)
This. For your requirements (4061s>battery box) I'm guessing your batt box has a 3.5mm plug for output which would make XLRs on the recorder unnecessary and give you the option of a smaller deck.
As vanark noted, the Sony has been discontinued and is becoming difficult to find, but its quality pre-amp and ridiculously long runtime on batteries make it a winner. I've been a very happy owner of an R-05 for several years and I find it to be a solid performer as well. Won't take quite as hot a signal as the M10, which hasn't been an issue for me, and it uses standard SD cards for storage as opposed to the micro SD cards that the Sony uses. The Sony uses a thumb wheel to adjust input, the Roland has buttons which can be locked. Both methods have their supporters and detractors.
Can't speak for the Tascam pocket recorders but they get praise around here from the folks who use them.
Anyway, all of this has been covered ad nauseam in the various dedicated threads if you wish to research further. Welcome back!