I'm busy doing a full rewire at the moment in an ex local authority property with a metal Clifton / Mantel enclosure, no room to swing a cat. I got the electric company to upgrade the tails to 25mm and asked for a meter move to bring the meter downwards to make room for the skeleton. No charge for this, in fact the company who came rents the meters to the electric company, so they were more than happy as they put a new digital meter in which was also smaller. I then went to upgrade the main earth conductor to 16mm but found the earth clamp on the supply cable too small to fit (TN-S), so the electric company came to upgrade the clamp but then just switched the supply cut out arrangement to PME.
The best price/option I could get on a skeleton was at TLC I bought a dual RCD with 10 way for a super deal price of 87.25+vat at tlc
10 Way Dual RCD Skeleton Consumer Unit + 100A Mains Switch with their usual free delivery was a bargain compared to quotes at CEF and others.
Check the widths of the skeletons, there are a couple of different types.
http://www.electrika.com/products/m/man-0150/pdftech/09-041.pdf - look at the last page, last section called skeleton. The inside measurement of the enclosure is what you are interested in... I then also had to do a little metal work, but the skeleton screwed straight onto the screws from the old fuse rail.
The next issue I had was that all the wiring was originally run down inside the cavity of the outside wall, which had also been cavity insulated with polystyrene beads. So I've re-routed it all, to prevent de-rating plus some of the cables sheaths had gone soft and sticky, maybe reacted with the cavity beads and bonding-agents or just got plain hot.
Enjoy.
