PlayExpo also have displays at tv and film comic cons, there's a big 3 day event in London each July. it'd be good if both dealers such as Amigakit, and Amibay were to take tables there, display customised Amigas etc.
There is also the PlayExpo North of the Border in Glasgow as well, as well as the same comic con in August, where they have a retro section, but it's usually just been NES, SNES etc.
It'd be good if an Amiga presence could be arranged / advertised in advance, I'd certainly plan on attending.