According to:

Missouri. Office of the Adjutant General
Annual Report of the Adjutant General of the State of Missouri, December 31, 1863

At: http://digital.library.umsystem.edu/

“THE 6TH REGIMENT OF CAVALRY, MISSOURI STATE MILITIA, Headquarters at Springfield, is well mounted and equipped, and armed with Austrian rifles, not at all suited for Cavalry service. The discipline and efficiency of the Regiment is very good, taking into consideration the inferior quality of the arms, and its efficiency would be materially increased if the men were armed with a good breech-loading carbine.
The Regimental and Company books and papers are well and properly kept, and the returns, etc., regularly made out and transmitted in accordance with the Regulations and existing orders.”

In regard to uniforms, the Missouri State Militia wore about the same uniform as the Federal counterparts (such as the 6th MO Cavalry).

There are a couple of sites on the WEB that have photos in their archives – The Missouri State Historical Society at St Louis has some photos of some of the soldiers in the 5th MSM Cav if you want to get an idea of what the uniforms looked like - I do not know the cost for copies.