Would be the only one I look at in that bunch - but still fear you might actually lose more than you'll gain. You'll get a distinct "dip" in midrange performance with any of these sub+satelite deals.
What's the rest of your setup? Since you're running a centre I'm imagining you already have an AV amp? What are the speakers you have at present?
Although I'm still very much on the side of having full-range, equal-output, voice-matched rears for surround sound; (what with my purely optimistic thinking that movie sound mixes should fully utilise the surround channels) the truth is that's typically reserved for BIG movies - and the surround channel information in most "other" movies is considerably less-pronounced and demands a lot less of your hardware (which is why you've still got the wall-of-sound effect in cinemas where most of the audio comes from the screen and the rest is played through significantly smaller satelite speakers)...
So what'd be my advice? Well assuming you've the AV amp, save your money on a complete re-equip and buy some surrounds, something like these say:
http://www.richersounds.com/product/bookshelf-speakers/tannoy/f1-custom/tann-f1-custom-dkoakThen when budget allows, consider adding a sub;
http://www.bkelec.com/HiFi/Sub_Woofers.htm(the Monolith if you can afford it, but any of these are better than anything in retail-stores, their budget Gemini model for VFM/SQ especially.Doing so would then allow you to free up headroom in your fronts (turning them down from "large" to "regular" or even "small" in your AV-amp's speaker setup) to get more from them... then, once that setups' lost it's glimmer, upgrade the front pair...
then the centre...
then the amp...
then repeat...
