I currently have a pre/power amp setup but would like true dolby surround, if not THX surround. But I do not know which is a better deal and better setup. Do I purchase a dolby preamp and do I need a dolby certified power amp to use too? Or do I just sell everything I own on ebay and purchase a nice thx reciever. HELP ME PLEASE I am slow on ths surround information but as far a stereo's im well veresed.