Who ever you go with, Leven, SVSi, TNT, Hennessy, Cauldwell, Sean Roe,just make sure you approach your purchase as a wise consumer. Do not release any $$ until everything in in writing. Make sure you keep accurate documents on your conversations, and do not think that something said in discussions are binding facts.
If you approach dealing with tuners the same way you purchase a house or a car, you should have little to no problems. The problems seem to occur when someone sends out a boat load of money with absolutely nothing to show for it. Would you give a realitor $10,000 without the proper contracts?
You might want to first learn how to get the most out of your Viper before you add even more untamed power?