After doing much research on systems we chose Texas Rainwater Systems. Barry, and his crew (Shawn and Dana) were all accommodating, professional, and very patient in answering all my questions. 

We live in a county that is under extreme drought conditions with wells going dry and not much hope of significant rainfall in the near future. Although we haven't personally had our well run dry to date, with the exploding population growth in our area, having this system gives us peace of mind. People are amazed that we have caught 30,000 gallons of water. After seeing how quickly our tank fills up we have future plans that include catchment from every out-building and more tanks.