Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.
What did you end up getting @ipedro ? Curious to know what you think about the Kanto Yaro's ... they're $100 off right now at Simply.ca, pretty tempting upgrade.
 
the only solutions I have found to avoid a 1980's style gigantic "receiver/amp" with 100 dials and buttons I will never press/turn and AM/FM which I will never tune into are these:
http://www.logitech.com/en-us/product/speaker-system-z906?crid=47
http://www.logitech.com/en-us/product/surround-sound-speaker-z506?crid=47

Of course various soundbars exist with optical in and dolby digital decoding, such as these:
http://www.vizio.com/home-audio/

All of the above have their own dolby decoding and amplification. You can simply connect your optical out from AppleTV to any of these and you're done.

Or if can afford it, SONOS has some nice speakers...

If you are not interested in 5.1 and want just 2.0 music, your best bet would be a pair of studio monitors with optical in (e.g. Behringer). They are self-amplified, so no need for an amp. Just keep in mind studio monitors are near field speakers, you don't want to sit too far away from them.
 
For 5.1, you could get something like the Logitech Z680s I have in my office. I don't think they sell them anymore, but they make some similar setups like the Z906.

surround-sound-speakers-z906-glamour-images.png
 
As an Amazon Associate, MacRumors earns a commission from qualifying purchases made through links in this post.
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.