most likely 18guage.
when adding an amp and door speakers i would always suggest upgrading to new wire of at least 16gauge if your gonna be running anything over 50watts. might not make a difference but overkill is better then choking the power from getting to your speakers.
hn155:rockford stereo, will have 2 t215's 2 punch pro tweets 2pro 6.5mids, t400.4 t1500.1bdcp.
perfomance build to come, lentach tranny, engine build for 250hp, turbo.