Thanks for the replies, everybody! We're thinking maybe it's better to get a receiver and separate Blu Ray/DVD. Instead of merely replacing what we had we "might could" upgrade a bit.
I found this in a review of an LG unit on amazon:
Set-up really couldn't be easier, though that convenience comes with its own set of downsides. Since the speaker wired are pre-installed, permanently connected to each speaker, you're stuck with them. And they are very low-grade speaker wires. Also, your speaker placement is dictated by the length of these pre-installed wires. This system is ideal if you have a relatively small-ish living room or are using it in a smaller room like a bedroom or study. Also, the fact that the rear speakers are wired is a pain in and of itself. Yes, wireless rear speakers are a premium but you may want to consider going with a more expensive system in order to have them.
http://www.amazon.com/LG-Electronics-BH5140S-Blu-Ray-Theater/product-reviews/B00IAELTLM/ref=cm_cr_pr_btm_link_2?ie=UTF8&showViewpoints=1&sortBy=bySubmissionDateDescending&reviewerType=all_reviews&pageNumber=2
Sooo---yeah, need to be careful about what we buy.