As above, and yes I used 4.0mm on the pivot blocks.
http://www.modelfixings.co.uk/
They sell M4 taps and the correct sized drill bit together I think. They also sell M4 high tensile screws. Ran my car all day today at Newbury, took some stupid crashes and not even slightly bent
Of course if Northy could do it all as a bundle would be ideal. If you are going to do it, 10mm and 12mm bolts are needed for front. I've not bothered with my back, not really needed I don't think. If I bend one, then I will.