You've researched and spent a lot for a quality instruments. The sape can be said of having a quality cable between your instrument and PA or amplifier really does make a difference.
My recommendation for a quality cable is any of the cables below. I personally have Analysis Plus cables as well as an Evidence Audio instruments cables. These are the best cables I have used and are somewhat reasonably priced.
The Zaolla Silverline cables really look promising but pricey.
For a more consumer and musician friendly priced cables try out Planet Waves, Monster, Mogami or Asterope
A Dedicated Instrument Cables Page
For more information on ukulele strings check out the Learning Ukulele with Curt dedicated Instrument Cables Page . A quality instrument cable DOES make a big difference.
Analysis Plus
Analysis Plus, Inc. has provided electronic and electromagnetic simulation and analysis for a host of companies since its inception in 1993. All the members of our team hold advanced degrees in Electrical Engineering or Physics, and our specialty is the art of computer simulation. We are experts in the use of Saber, Matlab, Ansoft, and Spice, among other tools, as well as in the testing and measurement of physical devices.
MOGAMI
Mogami has always had a relentless devotion to quality, integrity and ethical business practices. Every foot of Mogami cable is made in Nagano, Japan under the direct supervision of the company founder who continues to work every day. Comprised of true craftsmen, Mogami refuses to compromise quality for cost savings, and never copies the work of others. In today’s global economy, it’s often difficult to track who really makes a branded cable or other products.
Zaolla Silverline
Zaolla Silverline is the leading innovator of cable designs for the musical instrument and pro audio industries. From solid-silver conductors for digital audio and video interconnects to unique hybrid conductors for instrument and microphone cables, Zaolla Silverline tailors each design to its specific application.