Ken,
Just keep an eye out on B/S/T for a KL4. For that matter, what's wrong with a KL1. The beam isn't as pretty as that of a KL4 with the reflector, but it's every bit as functional and it costs A LOT less. Plus, the KL1 has a buck/boost circuit in it. 1X123, 2X123, 3X123 or li-ion. It's all covered. The KL1 will also host an NX05, Fraen LP, or a McFlood. The modded KL4, in all of its grandeur, isn't nearly as flexible as a modded KL1.
Don't get me wrong. I love the KL4 mods that I have. I wouldn't choose a modded KL1 over a modded KL4, but that's my preference, as it is with many others, in spite of the cost. The fact of the matter is that you could almost have two modded KL1's for the total cost of a modded KL4.