bb218,
Where in the world are you? It would be helpful if you had your location showing in your profile.
I an only offer the general information that most of the larger suppliers to the trade have lots of hold-down hardware.
Sherline and Taig have hold-down hardware for their small machines which might be useful. 10-32 fasteners, though.
Making clamping hardware is not too hard. I've made several small clamping pieces using 1/4-20 fasteners. I used pieces of 3/4 x 1/4 steel bar cut to length and machined as clamp bars to fit the application. If you are metric, them maybe 6mm or 8mm fasteners.
Have fun,
--ShopShoe