Iron Clad Plans

Cottage Industry Models has accurate cast resin kits of Civil War models, in 1:32, including Turtle, Hunley, a CSS ram, and others. He's a one man shop at:
Cottage Industry Models
1632B Ashley River Rd.
Charleston, SC 29407.
Their models were on the Modelers Boatyard web site but I don't know if they are still there or not. The address is from a 2000 "Ships in Scale" so I hope it is still good.

PS:
I agree with Jeff; Taubman's for plans!
Regards,
Bruce

Looks good... Thanks guys

Taubman's Plan Service is the way to go. Be advised, that Abe Taubman is well into his late 80s, so it does take some time for him to reply, the website is run by his family and friends.

http://www.taubmansonline.com/

They list a set of Arkansas plans as follows:

CSS Arkansas
Confederate Ironclad. Length Overall 23 inches. 2 sheets and 2 detail sheets.
StockNo: DM-9803Pg97
Scale: 1:100
Price: $25.00

Regards,

Jeff Herne
Modelwarships.com

I obtained a set of 1/48 plans of the CSS Alabama via the Smithsonian Institution. You could try them.
Best of luck
Dai