I have found that my big 'ol 3 and 4 D cell Maglights from years ago work well with the replacement LED modules. With a good module (not the cheapies you find in hardware stores) they are about as bright as my current 1xAA LED lights (when I run those 1xAA's on LiIon or NiMH). The Maglites are a lot bigger and less convenient obviously. But with 3 or 4 D cells in them, they have a long runtime. Good for backup lights around the house in emergencies. I would recommend re-purposing these old Maglites with low output LEDs rather then the newest brightest ones. Use the old Maglites for low output, super long runtime emergency use, not for eye-blinding brightness. Get a newer, handier flashlight for that.

But since you are talking about a 2xCR123 light, you can probably buy a whole new light for the same cost as a replacement module for the old one, provided you can even find a suitable replacement module in the first place. I would suggest just buying a new light, and giving your old one to a friend/family member. About the same cost to you in the end, but you would end up with two people having lights, not just one.