Speaker jumpers

At the risk of voiding the warranty, take a peek inside.

Duplicate the internal wiring.

Other than that, I'll vote with jl35; match your speaker lines.

Any other 'esoteria'....well, it's your $.  Do what you want. *shrug*  MHO.

Not only do some speaker companies give their customers poor jumpers, but also some manufacturers of integrated amps include poor jumpers. There are not many easier and affordable upgrades to equipment than replacement of jumpers. 

Just as itzhak1969 relates, the results are so profound that it surprises people. Congratulations to those who have tried and found a simple, but effective way to improve the system. 

At the least I would use the same cables as your speaker cables, just buy an extra length or cut some off the ends of your current cables. Anything fancier doesn't seem like it would offer a benefit. I did notice an improvement when I replaced my flat gold plated brass jumpers with short lengths of speaker cable.

It all depends on what is there now, really. And what you plan on replacing it with.

You could bi-wire and eliminate the jumpers. I use Magnan now. I have used SR, Kimber, and Stealth with positive results

You can always use audioquest silver links.  it is 16awg solid core wire and it provides good contact area in the binding post. $25.   I do not believe a second that upgrading such a short connection (minuscule resitance) can make a difference, but I hate to say it... i feel like they did compared to 16awg copper wires...