The correct light for you depends upon what you want to do exactly. All of the led lights today are constructed for a certain person in mind.
For example, the standard led light for police officers is the Pelican 7060 because its 1) politically correct in its construction, cant use it as a weapon 2) rechargeable 3) lightweight 4) throws a beam about 2.5 football fields. It was designed specifically for police officers by police officers of the LAPD.
http://www.amazon.com/Pelican-7060-R...3518133&sr=8-1
Whats good for the LAPD may not be good for you. I dont like the Pelican 7060 because I enjoy having a lot more light so I use the Fenix TK35. The 7060 also does not have certain modes that I enjoy having such as the strobe feature and the lower light settings. Its just on, off, and one power setting which is high.
In any event, I would NOT use the rechargeable 18650 or 14500 batteries at all. In the Fenix flashlight manual it clearly states to use 18650 batteries with caution and I believe all other rechargeables it says are "banned" from its flashlights. 18650 have safety issues. The safest way to go is to use high quality CR123a batteries bought from a known reliable source (Surefire, Streamlight, Duracell, Panasonic).