Tagging so I see what you end up with. I'm consider replacing my trusty and ancient Logitech Z4, which really seems to be a decade-old predecessor of your Z623. Interesting. I'm shooting cheap, but ...
Klipsch’s ProMedia line has been around for quite a long time. It dates back to 1999 when the original ProMedia made a splash ...
The Logitech Z-340s can be had on Newegg for ~$35. Just read the reviews for them on Newegg and other sites, people(including me) love them, and they're cheap.