The closest WILLIAM A. ENOS I find in the Roster of Confederate Soldiers, 1861-1865 is:

Enos, William TN Cav. 11th Bn. (Gordon's) Co.E

This might be your man. The 11th TN Cavalry Battalion [also known as the 10th TN Cav Batt] organized with six companies on January 8, 1862. Consolidated with the 2nd TN Cav Batt and designated the 6th TN Cav Reg as of May 1862. Lt Col William W. Gordon, commanding. They took part in the Corinth Campaign, April-June 1862.

TENNESSEE 6TH CAVALRY REGIMENT
AKA [1ST CAVALRY REGIMENT (USUALLY CALLED SO) AND 2ND CAVALRY REGIMENT]
Organized by the consolidation of the 2nd and 11th
Cav Bns in May 1862. Reorganized on June 12, 1862. Company "E" served detached as escort to Brigadier General Frank C. Armstrong from September 1862; to Major General Earl Van Dorn until May 7, 1863; and to the brigade commander until October 1863. Companies "B" and "C" served detached as escort to Major General Carter L. Stevenson from March 20,1864. Surrendered by General Joseph E. Johnston at Durham Station, Orange County, North Carolina, on April 26, 1865.

As for the name WILLIAM A. RHEA,

Rhea, William A. TN 5th (McKenzie's) Cav. Co.H
Rhea, William A. TN Cav. 17th Bn. (Sanders') Co.A 1st Sgt.
Rhea, William R. TN 19th Inf. Co.G Sgt.