welcome.
just checked that site and they are lovely fabrics. no wonder you want to use them. i agree that hand-dyes can be tricky. in fact, i would count on it. i would start right out with retayne, maybe twice, before using it. be sure to finish the edges to prevent fraying. i noticed that the fabric is not inexpensive so you don't want o lose any of it. what color family did you choose?
http://www.starrfabrics.com