Is the Samsung 20S in the queue? It's supposed to be the top 18650 performer - would be great if you can get a pair to test. The 24S is also good but hard to find. I have a couple 20S's, think bought here, in stock: https://www.18650batterystore.com/18650-p/samsung-20s.htm
It makes it easier to find it when the request includes a link where I can buy it (Remember I am in Europe, this means mostly from Europe and part of Asia).
Not really a problem, there are inexpensive and good chargers which can cope with LiFePO4 cells. As most notable examples the LiitoKala Lii-202 and Lii-100. This is not for sloppy users, to charge LiFePO4 cells you will have to press the MODE button to swap charging mode to Li-Fe upon cell insertion. A very easy thing to perform once accustomed.
Choosing this path will make you save money sooner or later; quite soon I'd say given the price :facepalm: of CR123A non-rechargeable lithium cells.