The Arkansas State Troops were very much a mixed bag in the Wilson's Creek campaign. Where any semblance of uniformity existed, it was only within companies; the five regiments and McRae's battalion being organized by grouping what had previously been independent militia companies. You had everything from the "marching band" uniforms of Fort Smith's "Belle Point Guards" to men wearing their civvie clothing from home. By and large many seem to have settled on some form of hickory or flannel overshirt over civilian shirts and trousers.
For the most part, weaponry was a mixed bag. The standard was the M1822 flintlock musket in .69 caliber, fring buck and ball or simply buckshot. Some companies were outfitted with more modern weapons such as the M1841 Mississippi rifle, others carried civilian hunting rifles and shotguns. Again, any uniformity would be primarily wihin companies. Ammunition was carried in open-topped cloth pouches since there were no leather cartridge boxes available. Sweeny's Museum outside the Wilson's Creek National Battlefield has an original example of one of these pouches on display, and I made a copy to go with my early war kit. They are simple, but functional, and don't offer much protection to your cartridges. In fact, a primary reason for the battle at Wilson's Creek happening as it did was that the Southern Army called off its march on the evening of August 9 when a thundershower came up and threatened to get their ammo wet.
Probably the best single source right now on the State Troops is to get a copy of Gary Piston and Rick Hatcher's book, "Wilson's Creek: The Second Battle of the Civil War and the Men Who Fought It, published in 2000. Very little has been written about the Arkansas State Troops and few if any records remain... most of what there is in contained in that book. For other ideas, a look at the Missouri State Guard, their tactics, and equipment, see the research at http://www.geocities.com/burbridgebn.