The Hyatt at Lost Pines in Bastrop....just outside of Austin would be a great alternative. Here is the link:
http://www.lostpines.hyatt.com/hyatt/hotels/index.jsp
Easy to get to as the new Tollway 130 from Georgetown goes right down to 71 and it is on the East side of town so easy for Houston drivers as well.
I have had groups of 350 there and they did a great job and they all kinds of Bars and Outdoor pavillions, etc. plenty of parking.