balanced cables do make a differnce with a dual differential design (it helps if you can run all balanced or connecting between truly balanced designs) once i heard my system fully balanced, there is no turning back...
here are some cable suggestions that are highly regarded and very good imo..
just as a heads up - it is is really hard to find a truly great cable for $400 and under retail that workd well in a wide range of systems..most sub price $400 retail cables do a couple things really well ( mid range, imaging etc.. but it is really hard to get high resolution at the frequency extremes (delicate/ detailed highs and thundering deep bass)
hope this helps..
discovery plus 4 (slightly warm)
straightwire serenade (great cable- a smige on the warm side but really musical. if you want brighter/more detail go with the maestro)
wireworld eclipse III (nicely balanced sound- between the serenade & the maestro)
soundstring (disclosure... i have a pair for sale for a little more than $200- high resolution neutral cable that is one of the best cables under $1k (to do better you will have to spend mucho $$$$$$-check the reviews..)
all are great, musical cables...
btw, dont forget about speaker cables and power cords !!!!!