Want help on what speakers cables to try.

Not new to this and been around the block to many times and really wanting input from others on what they may recommend.
Speakers cables only, Please.
Have the Audio Space 3.1 Reference 300B Integrated amp.
21 / 25 watts per channel. This drives my Silverline Sonata ( original ) which I believe is 93 maybe 94 DB.
These are Bi-Wire speakers.
2 of my favorites where: Harmonix, and the HT Pro 9 Plus.
I was thinking of trying the HT Pro, the newer cables that are suppose to be a step above the Pro 9 Plus then I read these are for "BIG" speakers and if you have a high powered amp? Well, my speakers are some what big but I am not going to part with my tube amp which is a far cry from "HIGH POWER".
My whole system is tube based other then my digial which I find I seldom use, prefer analog.
So, the question is: Try these new HT Pro, which happens to be bi-wire or try what ?
Have a good audiogon friend I put a lot of faith in on using Bi-wire or single ended. He prefers single ended and go with a good pair of jumpers. So I really will consider either. He has been in this longer then I have.
Should I be considering Copper or Silver ?
Like to keep the $$$$ around 600.00 used. Can go more if need be.
Thanks for your help,
Dave