I'm confused too. What are you looking for, a diagram of the exhaust system?
The stock exhaust setup is in this order, going from the engine back:
1. Turbocharger exhaust outlet
2. Factory catted downpipe
3. Factory second cat (what would become your test pipe section)
4. First reso.
5. Second reso.
6. Muffler
7. Exhaust tip.
I have no idea what ebay test pipe you may be looking at, who makes it, what the materials are, how well made it may be, etc. I'd suggest you go with one made by a reputable company that also makes a good downpipe in the event you want to upgrade to a dp/rp combo, so that it will fit properly.
I guess you know that reso delete will do absolutely nothing to improve your power. The stock CBE flows better that the maximum output of the K04 turbo. Reso delete will only change sound, but if that's what you want, please note that you might want to put the test pipe in first (10 minute job) and see what change in sound and volume that makes, as deleting that second cat will change the tone and volume. And if you ever go to a bigger downpipe, especially a catless one, the combo of dp/rp is really loud through the stock CBE. I had to add a reso in the test/race pipe section to tame that.