Hi Siony: 

There are many options and it's difficult to advise you without knowing the specific needs of your archives and museum collection. The Society of American Archivists delivers an online course to help frame your decision as part of their Digital Archives Specialist courses: http://www2.archivists.org/prof-education/course-catalog/archival-collections-management-systems

It may be helpful to see what other small universities in Arkansas are using, so that you have the option to collaborate. Remember to always consider ease of use, future expansion, and data extraction when considering a CMS. 

Best wishes, 

Jennifer