$600 5.1 speakers?

[sean10mm]

I have a crappy old "home theater in a box" setup and want to upgrade to something with decent sound quality to go along with my Mitsubishi WD-Y65 HDTV and Samsung BD-P1400 Blu-ray player. It would be 100% for watching movies.

For the receiver I'm most likely going with an Onkyo TX-SR605. I'll consider something else but the 605 seems to have everything I'm looking for for at a good price and gets good reviews everywhere. The features I want from the receiver are:

1) HDMI 1.3 connectivity. My cable box, Blu-ray player and HDTV are all HDMI and I want to connect everything that way.
2) Accepts PCM 5.1 over HDMI. Optional but nice: decodes bitstreamed DD+, Dolby TrueHD, DTS HD-MA.

Where I'm confused is speakers. I want a set of 5.1 speakers for about $600. I'm no audiophile and just want something that sounds good to an untrained ear and can produce decent volume in a medium-sized room without glaringly obvious distortion, which my current speakers can't do. The 4 satellites should be wall-mountable.

The JBL CS6100BG is the kind of thing I'm looking for in terms of size, packaging and price, but to be honest I have no idea if it is a good match for the 605 or is crap in general or what.

Any suggestions would be appreciated.