I do not know if your coastal zone 8 climate is different from mine (I am not on the Gulf coast), but I grow a variety of clematis in my yard, Clematis Jackmanni, Dutchess of Edinborough, Sweet autumn clematis, just to name a few, and some others - names of which I cannot recall right now.
Maybe you want to check out the American Clematis society's home page and make a search there based on your zone. You will find quite a lot of named cultivars there.

Here is the link that you may find useful:
http://www.clematis.org/,
and
http://www.clematis.org/clematis_a-z/index.html?zone=8

Good luck.