Here are some links I think are good if you haven't already found these. I really like any publication from A&M Horticulture.
http://aggie-horticulture.tamu.edu/galveston/publications/Creating-the-Tropical-Look.pdf
This used to be a great gardening forum, but I haven't checked it out since Houzz took it over. (Please don't ever let Houzz take over TFP!!!!) But this thread has good info and nice photos even if it is from 2007.
Help! Tropical Plants in Texas?
Not all tropical in the below link, but some would work or complement a tropical garden.
Going Native: Our Top 10 Native Plants for Houston | Buchanans Native Plants
Specific for the Hibiscus - gotta have Hibiscus in a tropical yard... This link also includes the Texas hardiness zones.
http://aggie-horticulture.tamu.edu//galveston/educ_programs/Tropical-Hibiscus.pdf
A&M's Texas Superstar Plants is a terrific listing of plants that A&M gives it's gold seal approval. I've used some, and they are the best varieties. I'm not sure there are a lot of tropicals, but many would work.
Texas Superstar
(I hope you appreciate how difficult it is for me to give all these Aggie links since I'm a Tea Sipper......)
Lastly, here's an interesting but brief article from Austin (had to put in a nod to UT) giving tips on how to get a tropical look. It also lists some plants they recommend.
http://www.statesman.com/news/lifestyles/home-garden/get-the-feel-of-a-tropical-oasis-with-texas-friend/nRmmt/
I hope some of this is helpful.
Happy plant hunting!
Suz.