This Cali resident must be moving in reverse because I went from the M3 to the E2!
I really like your soon-to-be KL1 addition but I'll swim downstream here and suggest that you might want to really go hog wild on accessories and batteries before getting another light. While more lights is always better, perhaps building a base/system out of your E2e might be a good idea. Get all your "E" stuff taken care of e.g., spare bulbs, holster, filters/beamshapers and plenty of batteries. Once you have the batteries you then have a perfect vehicle to move on to another light.
Having said that, unless you need the sturdiness of the M3, have to have the combat grip or for that matter just plain want one for the neato factor, I'd suggest something a little different. A 9P (an orginal model w/o the clip) with a LOTC and the M2 black bezel is a great workhorse that you'll really love. It gives you the 9v that you're looking for and will, I guarantee, become one of your favorite lights. It has the black body that isn't as rugged as the HA finish but unless you're in the jungle eating snakes and bugs, you'll be just fine. Scratches are personality!!!
I have several Exs, an M2, M3 and others and I just really love my 9P. I personally like the orginal models without the clip although you can, if you'd like, get one with it. I'm also a big fan of the KL1 on either the E1 or E2 but not the E2e. That's another post...
Good luck.