Matching surrounds to the fronts...

Hi, about 10 years ago when I got into DVD, I purchased a 5.1 AVR and a pretty pricey speaker setup. The speakers were Acoustic Research 310 HOs, matching center channel, and matching powered sub. At the time that tapped out my budget and for surrounds I used 2 Radio Shack "Optimus" floor speakers raised up off the ground. So here we are 10 years later and I never got around to upgrading the surrounds. I could definately tell they weren't tonaly matched to the fronts, but over the years i just forgot about it and it hasn't bothered me. However recently while perusing through ebay I found a seller selling two center channels speakers, the exact same model of center channel that I have now! Would it be worth it to get these center channels and use them as my surrounds, and finally timber match my entire setup, or should I keep searching for AR speakers that are more bookshelf type for more bass?


Thanks


Mark