When looking for cloisonne wire sizes I like to use Hauser Miller. They are also whom I like to order my Cloisonne bezel setting wire, for setting the cloisonne jewel. Here is a link to their site, http://www.hauserandmiller.com/
Although I prefer to set my cloisonne jewelry with 2.5 mm high 22k gold bezel with a thickness of 26 ga. and this is not on their chart, but they will supply it for you. When I am working in silver I will use the same sizes of wire for my settings just in Fine Silver.
Lower on the page is their stock of cloisonné wire sizes, this is 24k gold wire. The two marked with the * are stock, readily available. The .005 x.040 is the taller cloisonné wire and the .008. x .032 is the shorter in height cloisonne wire sizes. I like to keep on hand 26ga 24k gold round wire as some times I need to draw it down, then roll it out myself to create a very thin and short cloison wire as here on the back of these earrings.
The total thickness of the cloisonné earrings is 1.5 mm. with a 24 ga fine silver disc in the center where is not much room for my cloisonné wires, yet I have them on both sides of the fine silver disc. The wires might be 1/8 of a mm here.
On the front of the same earrings, you can see the wires are thicker and a bit higher. It is nice to be able to customize these wires to your need.
When Andre 3000 from OutKast order the Mandrill Cloisonne Pendant, he wanted thicker cloisonne wire sizes in the jewel. Here I cut the wires from fine silver sheet to achieve the look he was after.