I have a QK2A-X and a few QP2L-X burst modes.
Yes the light should come with the guts and boots of both reverse and forward clickies - you have to swap them into the single provided aluminum clicky housing. You do not get 2 fully assembled tailcaps. Only the reverse tailstands, the forward mechanism and boot are longer, or as per the picture above, you could buy the optional shrouded forward clicky for the Turbo line, but it is wider creating a knob.
An 18650 will not fit, but a Keeppower 2500mah 16650 is an excellent alternative. Illumn.com sells them.
The UI is different from the older Quark Pros and Tacticals - they need to program the light for you (custom models). You pick the modes and sequence you want and the light has mode memory, and 47s spin on memory is a little different from others. For example, if you choose mode 1,2,3 and turn on on 2 from memory, then the next scroll will restart from the beginning, or mode 1.