This is out east of Dallas a ways, but they have a variety of shooting matches, rifle, pistol, rimfire and shotgun. The range is private, but you can attend matches without being a member.
http://www.tr-pc.com/
These guys are a little closer to you. They also have a pretty good variety of shooting matches, but no shotgun.
http://www.haltomcityrpc.org/matches.html
If you're looking specifically for IDPA, this club is fairly active.
http://www.ccidpa.org/
Don't know anything about these folks, but it's probably worth contacting them.
http://www.meetup.com/Dallas-Target/