What is the difference between L293D and L293NE?
D = diode

L293D has output clamping diodes for inductive transient suppression while the L293NE does not. Since you're going to drive a motor you will want to use clamping diodes to avoid inductive spikes from the motor killing the output transistors in the chip.

If you can only find the L293NE you can add your own diodes. See the datasheet for how they are connected.