I would take a serious look at the Hovland Music Groove 11, it retails for 795.00 but you should be able to find one used in your price range. They aren't much to look at but I find it one of the best phono cables available. Good luck.
Best Tonearm Cable Under 600.00
I am using the tonearm cable provided with my Origin Live 250 Silver Tonearm which is connected to a Black Cube with PWR Power Supply. Should the same brand recommended by you very knowledgeable fellow members for the tonearm cable be used between the Black Cube and my processor?