So, I completed my install today. Used the Pioneer TS-WX11a as recommended by Neil.
There's not much to show really as its all in the sound, but I am really happy with it - more than enough bass for my taste, although for the soundoff crowd it would not cut the mustard.
In the end I went for an in-cabin install. There was not a huge amount of difference between the boot and in the cabin, other than how hard you needed to have the thing working. However, I found with the unit in the boot the sound was a little muffled and less clear. With it in the cabin the bass is particularly clear and punchy.
Thanks to everyone who took me from rank amateur to semi-competent ICE installer, in particular Neil_r.
Steve