Yellow/orange plugs are always SRS/airbag related.
Looks like you have an older 20 series (2008 - Apr2010)
Standard 8 channel amp, with the digital tv box in blue on the right (because i bet you have minidisc player in headunit, tv box had to be external due to space, and in later models minidisc was removed and tv box integrated into headunit), IPA is the larger box on the right.
Confirm speaker number?
Centre dash, tweeters in corners near windscreen, 1 in each front door, 1 in each sliding door(no tweeter in the plastic trim above sliding door locks), 1 each side in rear, which means you should have a sub under drivers seat for a total of 10 speakers, in which case you get an 8 channel amp (centre shares front channels, and sub has it's own amp)
The lower spec does not have centre or sub.
The 18 speaker system adds 6 roof speakers, and two tweeters in the sliding doors above door locks.