You don't need anything else, the D1SC will mount up to your existing bracket, tubes, etc. You can send your head unit back to Procharger with a check for about $1200 for the upgrade and they'll send you a D1SC head unit. Price approximate, they charge an inspection fee for your old one, a little more if you want polished, etc.
Or, if you want to buy the D1SC head unit outright without trade cost is about $2500 or so from a dealer.
2005 Sonic Blue Auto GT, ordered new
Thanks JPC Racing!