Help choosing a drop in for a Solarforce L2m body

I picked up a Solarforce L2m body and am trying to decide on what drop in to use in it. I plan on running it with 1 x CR123 battery. My current daily light is a G2 with an older M60LL drop in that I love so I figured I would go back to Gene for another one of his drop ins to use in the L2m. It seems from my reading that the L2m will take P60 style drop ins which should equate to a M61, however since I will only be running 1 x CR123 would the M61 still work? It seems that the M31 would be the correct choice. Any input would greatly help.

M31 sounds like the correct choice for you. Personally, I'd go with the M31HCRI while they're still available.

Drop-ins are not really modifications, so I'm moving this to LED Flashlights.