Are these for pre-tapped holes or will they have nuts?
Model engineers often use BA series fasteners, these are a strange british version of metric and are not compatible with ISO metric, but if you're using nuts then no problem.
There are a few model engineering sources in Australia, one I've gone to a few times is Hobby Mechanics:
http://www.hobbymechanics.com.au/categories/Fasteners/
BA8 by 1/4" would be about right, it is 2.2mm diameter.
BA9 is 1.9mm but HM doesn't have nuts to suit.
They do have BA taps and brass hex stock tho if you're adventurous enough to make your own nuts, very easy on a lathe.
Brass BA round head screws:
http://www.hobbymechanics.com.au/bra...ws-round-head/
Brass BA nuts:
http://www.hobbymechanics.com.au/brass-nuts-hexagon/
Both are about $6 or $7 for a pack of 25.
Other head types available.
BA screw info and chart of sizes:
http://en.m.wikipedia.org/wiki/Briti..._screw_threads
"
BA threads are still used in some precision instruments, such as optics....."