There are two existing flags for this unit - one the regimetnal color and the other the flag of Co.D, lancaster Cavalry.
The latter flag is in the collections of the Museum of the Confederacy and they can provide you with a wonderful color picture of it for a fee. It is a VA state flag.
The regimetnal flag is in private hands and was sold by Gary Hendershott some years ago. It is a homemade ANV style flag but rectangular. He has old catalogs posted on his website at www.garyhendershott.com and, if that is still the case, it will be available for you there.
Hope this helps.