Go to your favorite store, take a deep breath, and go to the lady with the batteries behind the counter.  The Energizer lithium batteries cost way too much money, but they will work. I put a set in my camera and have yet to replace them.

Oh, and as for Ni-Cads, if you are recharging them too soon you are ruining them.  Ni-Cads are very finicky and very unforgiving