Larry,
Anything from an 1816 Springfield to a 1842 Springfield would be your best choice. I had read a an account from Walker`s Texas Division they they did not receive more modern weapons until after Pleasant Hill. They threw down their smoothbores and flintlocks and picked up better weapons off the field. I tried to find that information but I could not find it. I`m sure there are others who could interject on this subject as well. My GG-Grandfather was also in the 33rd Arkansas Co. G.

Regards,
Larry Young