As I always say, it's best to stay away from eBay for wigs. The quality is typically very bad, most photos are stolen, and unless you have a head a mere 21 inches in circumference, the wig ain't gonna fit.
I would look through the medium length wigs at Arda-Wigs.com. The fiber quality is top-knotch, and they will fit people with larger heads. I think this wig looks good for the character. http://arda-wigs.com/collections/eowyn
Fandom Fest 2014 cosplay: GLaDOS (Portal), Ellie (The Last of Us), Lara Croft (Tomb Raider 2013)
MCM London Comic Expo cosplay: Oktavia von Seckendorff (Madoka Magica), Fem!Slenderman,
Future cosplay: Faith Connors (Mirror's Edge), Lara Croft (Rise of the Tomb Raider), Tetra (The Legend of Zelda: Wind Waker)
2015 conventions: Anime Los Angeles, Anime Central, Japan Expo