I've got an all-Adcom system (GTP-450, GSA-700, GFA-545, GFA 535. GCD-700) currently. I'd like to add a GDD-1 to the GSA-700 to gain Dolby Digital capability. Finding a GDD-1 has been tough lately-eBay and uBid are a little sparse right now. Are there any other add-on surround processors out there that I should be looking at? I like Adcom equipment, but I'm not so attached to them that I wouldn't consider other products...I'd like to keep the quality at the same level or higher than what the Adcoms provide.