My name is Ernest and I own DJ Masquerade, thank you for your question. The Alamo is a historic location and I am sure there is a lot of red tape and clearances you should call first and check on all the do's and don'ts here is something I cut and paste for you to research your question
Phone: 210-225-1391 Address: 300 Alamo Plaza Directions: NW of the Riverwalk Mall, downtown Website: www.thealamo.org
Here is a great blog from a couple that visited many different venues in the Austin area. They even created a top ten list! The couple ultimately chose Memory Lane Event Center as their favorite. Hope this helps.