Hello tattoosteve99,
Assuming you want to remain incan with the unit, your best option IMO is to use a pair of IMR16340s from AW and pick a "9v" style lamp for it. There are tons of lamp options to choose from but be aware that most of the options will be brighter but with less runtime than the stock P60 on CR123s. The ES-9 will most closely represent the output of the stock P60 but runtime will drop to about 35-40 minutes. (rechargeable cells in this size class don't have the energy density of primary cells, so there is some sacrifice). You can also move up to something like a P91 and pump over 300 torch lumens fresh off the charger. (10 minutes runtime) There are plenty of options in-between out there as well.
If you are thinking about going in the direction of an LED, then your best bet would be to use a 17670 size protected lithium-ion cell and drive one of many possible LED drop-ins out there. There are so many LED drop-in options that it would be impossible to go over them all in this single thread, but to sum it up, your options range from around 80 average lumens with several hours runtime to several hundred lumens lasting around an hour or less and many option in-between.
I think you will find the links in my sig-line to be of much help.
Happy lumen hunting,
Eric
