Jumper Cables - use the stock or should they be upgraded ?

I would use one run of the best speaker cable I could afford, and a jumpers made by the same manufacturer, rather than bi-wire cable of a lesser quality and no jumpers

I have used the Nordost  Reference Bi-Wire Jumpers and they were a major upgrade over stock jumpers... without doubt. The quality of the speakers you own... and your ears... will benifit highly.

With that said... I now bi-wire my system with identical speaker runs. My opinion is if your speakers have high resolving power...go with bi-wiring. Its a much more expensive proposition ... but the sound quality improves dramatically.  my 2 cents.

.....the current speakers cables are the Cardas Clear Beyond and a 2.5 meter pair were almost 5 figures......ouch. They took me awhile to pay off. I will check with Cardas as getting another run of those speaker cables in order to bi- wire is out of the price range. I will check with them to see what jumpers they have or would you run / use another company's ????   

I would use jumpers made of Cardas Clear Beyond if available

Whilst we're on the subject, jumpers aside, different results may sometimes be obtained from connecting the single wires to the upper or lower set of binding posts.  Some do one upper and one lower.  It's worth a try.