It's somewhat hard to find a place that sells tons and tons of wall scrolls from different anime series, since most places carry wall scrolls from popular animes. However, I found three sites that look fairly decent and have a good selection and amount. Of course, Sailormoon, Sakura, and Kenshin will always remain there but there's a few other series.
Animenmore.com- Import Anime Store
AnimeNation
Toys N Joys Online
I hope these helped and if you're still looking for more, please tell me what sort of series you're looking for and I'll try to help look.
