Upgrading speaker cables...

Currently, I have a Cambridge Audio CXR200 that has a bi-amp feature on it. I have 1 channel going to lows, and 1 to highs for each side. So, 2 pairs of cables for each side. 

I'd prolly have to go down the line on the cables if I had to buy 2 sets.... So, would I be better off with 1 set of nice cables with a set of jumpers, or 2 sets of lower down the line cables for them?

Reason I'm looking is, I have cheap cables currently, and was told a nice set of cables may open up my speakers (Wharfedale Reva-4 towers) and make them sound better. 

Thanks for for any help/suggestions!