The KL1/KL3 (newest versions) has an optic that is meant for throw and not up close work.
The KL4 head offers a flood light with large spot and plenty of sidespill.
The 2 cell SF E series body and tailcap (either Z52 for LOTC or Z57 for clicky) with the E2C step-up adaptor and KL3 head will work.
The KL1/KL3 take from 3-9 volts which means you can use rechargable cells in then either 1X or 2X.
The KL4 MAX is 2X primary 123's or 1 X RCR123 in a E1L body.
It depends on what you want in a light, throw, or sidespill. You can have both with the KL1/KL3 with attached beamshaper, BUT this adds bulk.
If you want, you can put a KL5 head on your E2L body with E2C. This offers the best combo of sidespill and throw.
Jason