Serveral of us have been working on a cross referenced list of Arkansas Civil War Confederate units. This list was developed by cross referenceing units listed in several sources including:

Sikakis, Stewart, Compendium of the Confederate Armies, Florida and Arkansas, Facts on File, Inc., 1992, ISBN 0-8160-2288-7

National Park Service, Civil War Soldiers and Sailors System, http://www.civilwar.nps.gov/cwss/regiments.cfm, which is really based on Joseph Crute's Units of the Confederate Army

Edward G. Gerdes Civil War Home Page, http://www.couchgenweb.com/civilwar

If you have suggested corrections or additions I would greatly appreciate you input!