I have one of the China spec Ebay
TBE systems. Gotta say, that I am very very happy with it. Just because it was cheap. Does not mean its a bad system. It sound good, does not drone. Fits up perfectly and all for $650!
Honestly, seeing as you have no intention of changing the td04 out for something bigger. I would recommend one of the china spec systems. Just change over the muffle later to a twin tip unit and your done.
However if you do change your mind and later want to chase some serious numbers. A Split dump pipe that has a separate pipe for the wastegate would be benficial. This can always be added on later.