OP, you are on the right track seeking a pair of cabs for your drivers.
At 15.5 pounds, the K140 is much lighter than the 22 pound E140.
Two cabs are more expensive up front, but are more flexible and easier to move.
The cab size and tuning depend on your requirements. K140 Flat vs EBS
The JBL Enclosure Guide has no entry for the K140.
The above EBS is close to the JBL recommendation of 4.0 / 40 Hz for the E-series.
T/S are from JBL, chart is WinISD.