Check MSC Industrial Supply at http://www.ganoksin.com/gnkurl/15w for
perhaps the widest selection of end mills at one place. They stock
end mills down to 0.0050 inches in diameter. Of course these small
mills won't have a 3/32" bur shank, so a very small chuck will be
needed. MSC carries tiny precision chucks with stright shanks that
will allow tiny mills to be used in drill chucks that do not go all
the way down to 0 inches.
MSC is a reliable supplier. Once you get on their e-mail mailing
list, they send out frequent sales offers, such as "30% off on any
order over $250" or "25% off any order of 5 or more different items."
I keep a running list of bits and end mills, ordering when a discount
The Millrace Studios