PCB Milling bits in the UK

Hi,
I'm rather new to this (and to the group), but I hope you can help.
I'm putting together a small milling machine to use for PCB milling.
What I'm looking for is advice on what cutters/tools to use to do the
track isolation and the best place (in the UK) to get hold of these
tools. So far I've been using 1mm carbide slot cutting tool and
though this works well it is rather large for some layouts. From
looking at other posts and web sites (the search engine for the Yahoo
groups seems really bad BTW), it seems that what I may need is some
sort of cutter with a 60 degree angle to it. Presumably you then
control the width of the cut by contolling the cut depth. Is this the
best way of doing things? Anyone any recommened UK based suppliers...

Many thanks

Andy