I was considering the E-110's too, I have had a great time using the K-110 2x10 cab with my jerry rig. I have always been scared to use them too much or too hard though, original cones and all. They do push easier, and are brighter than a k120. Maybe its just a lack of lower end in relativity. I never got around to my E-110 stack, but I am sure they are a great high efficent speaker. For lower volumes, my k-110 cab sounds great, but when I say lower volumes, its still pretty loud. For a real Jerry experience the K120/E120 is really the way to go, the subtle difference across the sound spectrum is there. But still, a k-110 is an awesome speaker. I can't see the E-110 being bad.
I am very intrigued with the D-123 for low power JBL tone. That seems to be a pretty smart choice for a low powered rig.