The 2 Eneloops.
In series, add voltage and mah stays the same. So V for 2xNiMh ~ = 1xCR123, and mah would be 2xNiMh ~ 2000 (2500 for XXX), 1xCR123 ~ 1500. One other alternative you have, is the 1xCRAA/14505 cell, which is essentially a CR123 equivalent in a AA body - unfortunately, it's been out of stock for sometime now (although I have small stock of them). Keeping the 1xAA body (and carrying the 2nd cell) would give you a lot more options, like scavenging AAAs and 9V cells - which for me = emergency runtime.
Since you seemed very concerned with emergency runtime (as I am - we've discussed the D40A in PMs), I'd just go back and use that LD12 body with Quark head if I were you... between its ultra-efficient AND bright useable moonlight mode, broad voltage support and Lego-able bodies, and ability to scavenge any cell with <19mm diameter, it's the ultimate emergency light for me. I know Fenix claims ~ 300 lumen-hours of efficiency across all its modes, but I read SB's tests, and adjusting for battery and lumen scale difference, the LD12 doesn't seem significantly more efficient than a Quark to me.