I had exactly the same problem and used two lengths of 40mmx25mm mini
trunking side by side to feed into my comms cab.

The stuff I used was the Min 4 Trunking from TLC, it's 40mm wide and
25mm deep.
http://www.tlc-direct.co.uk/Products/MTMIN4.html

If you look on this page:
http://www.tlc-direct.co.uk/Main_Ind...g_4/index.html
at the bottom is all the angle peices, flat connectors, corner
connectors, T peices you might want.

Hope this helps.

Seri