i don't think you can get a good pair of 5.1's in your price range.
there the really cheap creatives and the new altecs, but it isn't anywhere near the promedia's 5.1
i have the z560's, and yes i recommend them despite the horror stories you've heard of, because they are nice for the price and it sounds great. personally i took those stories into consideration, and bought a warranty...
get the z560's you won't be disappointed, read those reviews too... i'm sure you don't really need a 5.1 system