Check with Mariner Sails, they may have some demo boats you can go out an pedal on White Rock lake and they will help you find a good deal on a boat.
A lot of DFW comes here for Kayak sales or craigs list, TKF forums usually cover the coast and ACK forum is the Austin/San Antone area place to look for boats.
Hope your search works out and you get the boats you want!
Bert"Ipsa scientia potestas est"
-Knowledge in itself is power - Sir Francis Bacon "Beware the lolipop of mediocrity, one lick and you could suck forever"
- unknown author