Save your money and do the "stealthback" TurboXS. That is the catless dp/rp connected to the stock CBE. Believe me, the dp/rp combo will make the exhaust quite a bit louder just connected to the stock CBE. I had to put a 3 inch high flow reso in the middle of the test pipe to tone it back down a bit.
Too many people fail to understand that the stock CBE is excellent. It flows at a higher rate than the stock turbocharger can produce exhaust at maximum output. There are no power gains to be made, NONE, by spending money on the CBE.
The restrictions are upstream in the poorly shaped and restrictive stock dp and those two "low flow" cats. That's where you need to do the work and save your money from the CBE for other power mods.
As to power gains. Yes, combined with a good intake expect to be about 40-45 horsepower up on stock. More importantly, the gains are fat and broad, throughout the entire power band, coming on earlier, with fabulous gains in the midrange.
You will need to monitor boost levels, as the combo does raise boost about 2 psi over stock.