987 PCM 2.1 with Bose, Upgrades

[Rethw]

I’m looking to replace the old PCM2.1 with a double din Sony XAV-AX5650. I know I need the correct Bose kit without steering wheel controls, but my question is, is it that simple ?
Just connect up the new harness to the existing and the new into the back of the new head unit. Or do I need to undertake some re wiring ?
Also the DAB aerial supplied with the kit looks awful, does anyone have experience of fitting a discrete solution ?
Thanks G.