I wouldn't bother with the IMR-9L unless I was going to run a pair of IMR18650s, it needs plenty of voltage under that load to really wake up. If you want to run a D36 head on there I would suggest the EO-9L as the absolute maximum. Coincidentally, the EO-9L is about the same power consumption as the IMR-9, but I feel that the different bulb style found in most of those D36 LAs is of higher efficiency than the little D26 bulbs.
If the intended cells are going to be those little IMR16340s, and you want to stick with the D26 platform (floodier beams), I would go for the P91 to really see something impressive in this size. The IMR-9 makes sense when you are going to run a pair of large cells. When running large cells, it stands to reason that one would be interested in having runtime, which would also translate to a desire for reasonable bulb life. In the case of a configuration that is going to run for less than 10 minutes, bulb life just doesn't really matter. It's either going to run for 2 seconds or 10 minutes, either way, it's not long enough to get much done and you'll probably feel compelled to carry a reliable backup whether you have the bulb life or not.
Eric