HobbyKing plug & play Aircraft Engine Sound Module System(SMS) $40
Runs on 3-4S battery, Connects to the models ESC and outputs
an engine sound based on throttle setting through a speaker (supplied).

ESC Dlux HV 120A 6-12S No BEC $150

ESC Dlux 100A 2-6S SBec $80

Dr Madthrust machine gun sound sim module(with speaker) and
dual flashing LEDs(gun flash) Module.
Needs a power switch module to turn off and on(not incl) $15 for both.

ASSAN Door and Gear sequencer
Input: 1 servo Channel.
Output: 3 Channels (retracts and 2 x doors)
set up via 4 buttons on the reverse of the sequencer which
also features a large, easy to read LED display $15

Pickup from Hampton 3188 or Post at cost.