I know there are quite a few tropicals that can grow here without protection, but are there any that can grow her without that much water? Is there any ways that they won't need as much water?
Look for the lusher drought tolerant species for a tropical look:
Texas Olive (if it's hardy in your area)
some of the Texas Rangers (the green foliaged ones)
oleanders, bougainvillas, thevetia, are drought resistent but are sensitive to frost.
dalbergia sisso is small sized tree that I believe is not sensitive to frost.
lots of annuals--portulacea, cosmos..etc
bottlebrushes, bush morning glories i believe are frost tolerant.
Anyplants will need some water until they are established.