I have a set of AT831's just setting here I need to get rid of. I have had really good results with them and are nice and small for those special situations. Smaller than the Chruch mics I think.
I wasn't going to recommend equipment I've owned, but since you have, let me just say that SP-CMC2s (AT831s) make killer first mics. I've owned mine since Nov 2002, and used them to make 300+ recordings, including a few officially released by bands.
Even after upgrading them they still come out on occasion.
They work nicely with a 9V battery box, and either Nomad JB3, or iRiver H120.
Where are you based, s-r?