Hello Supawabb,
In spite of how those cells are labeled, R-CR123 cells tend to come in at around 600 mAh. The "3.0" volt R-CR123 cells usually come in under that and he LiFePo4 chemistry, it is less energy dense than the normal R-CR123 chemistry is, so your capacity will be even less. In addition, you will get the most cycle life from your Li-Ion cells if you limit the discharge to 80% of its total capacity, so your usable capacity drops a little more. Primary cells are at 1200 - 1500 mAh.
The units you linked to are for different cells than what the WF chargers charge. Keep in mind that when you go for 3.0 volt R-CR123 cells, you may be locked into the charger that comes with the cells. The same goes for the LiFePo4 cells. The WF and other Li-Ion chargers are for cells that end up at 4.2 volts fully charged. This higher voltage can cook some circits in lights, so you have to be careful. Even the 3.0 volt R-CR123 cells can come off the charger at too high a voltage for some circuits, so be careful.
You should take some time and figure out how much you use your light. If your light runs for an hour on primary cells, and you go through 2 sets of cells a night, you may be a good candidate for using rechargeable cells. However, since the runtime with rechargeable cells is less, you will have to have spare cells charged up and ready to go.
If, on the other had, you only use your light for around 15 minutes a night, and you normally get around an hour of runtime from primary cells, you will only have to recharge around every 4 days. This is very manageable and you will recoup your investment in a couple of months.
If you are looking for a good charger for normal Li-Ion cells, check out the Pila IBC charger. You will have to get a spacer to charge R-CR123 sized cells, but it does a good job of charging.
Tom
