Good news for you, you don't need to get the N9000ES for it to work. You just need an amplifier. You see, if you go to a Best Buy or some such store they sell lower end solutions for surround sound in the form of what is known as a receiver. A receiver is made of two essential parts, a preamp/processor and an amplifier. The Sony TA-E9000ES is a preamp/processor, it decodes a signal, controls audio levels and other parameters as well as switching between various components such as CD players, Tape decks, DVD players and other gear.
An amplifier does just what the name implies, it amplifies a signal for output to speakers. It takes low level, but variable (volume controlable), output from a preamp/processor and increase the power to be fed to hungry speakers.
Now, the reason you don't need the Sony TA-N9000ES amplifier, preamp/processors are all pretty standard concerning output, so you can connect it to a large variety of different amplifiers ranging outside the Sony brand if you should chose (this is likely the best choice to look outside the Sony brand for amplification anyway).
There are a plethra of brands of amplifiers out there to look at, the best suggestion I can make is to set a budget and we will continue to help you in your venture to pursue audio nirvana.

You have stumbled on one of the best pieces of Sony's audio legacy, and they are few and far between.

Did this one by any chance come with a remote, and if you don't mind my asking, how much did you get it for?
Test it via headphones on the front of the unit with a source connected, such as a DVD player or CD player.
Good luck, and we look forward to hearing from you. Send me a PM when you return.
Seth=L