Hi,
I was in the very fortunate position of having a full Bose system already in my possession and only had to pay for the fitting, all of which was completed at the expert hands of Tom (Timmus). He is an absolute master at working his magic on A2s. I highly recommend sending him a PM as he can quote you for a complete install (on your driveway) which will include absolutely everything (opposed to some of the 'full' kits found on auction sites which don't come with the Bose speaker gills, amplifier bracket and drivers footwell tool storage insert) needed for the OEM feel.
Kind regards,
Tom