No problem, we're here to help!
The 3 different systems comprise of:
1x centre box and rear box with straight tail pipe.
2x centre boxes and rear box with straight tail pipe
and the 3rd system has a downward pointing tail pipe that I can only assume is for a diesel variant.
Many of us with custom built systems don't pay out £1100! I have a dBilas 4-1 cast manifold, 2.5" S/S custom downpipe inc. 200cpi cat and 2.5" S/S Milltek catback system that comes in at around £1100.
HiQ must be having a laugh lately anyway. An old dodger that lives a few door down took his Nissan Micra to HiQ in Bristol last week for a new tyre. Whilst there they advised him that he needed his front brake pads replacing. They charged him £130 just for supply and fit of pads!!