For speakers in the 650.00 range, I think the Energy Take 5 system is hard to beat, but there are other good choices. Klipsch Quintet sound pretty good for the very low cost you can find them for.
If you are willing to go the DIY route and have the skills tob build some enclosures, I would highly recommend making your own speakers, or considering a kit.
Is your basement unfinished as of now? There are a couple of options that I can give you if you are interested.
