Thick or thin speaker & interconnect cables ?

I have ss pre & tube amp (only 10w/chanel single end).Which cables (interconnect & speaker cables),thick or thin are worked best which my combination?
I know of no way to sonically describe thick and thin cables. There are both thin and thick cables that sound great and some that do not.
Let me offer my limited experience. I own a Moth s45 SET amp that outputs 1.8-6wpc depending on output tube (either 2a3 or 45) rectifier tube and bias point. After reading many posts on the benefits of small gauge solid-core wire, either silver or copper, I decided to try it myself. My existing bi-wire cables were typical Audiophile fare; Silverline Audio copper cables that match the internal wiring in my Silverline speakers.

I substituted 24awg (5n) 99.999% pure silver wire with 20awg teflon tubing, bare-wired to the top-posts, while keeping the Silverlines on the bottom (for now). RESULTS: IMS the performance was much improved, paralleling many of the benefits of SET amplification itself. The cost of $64 for a 10' pair was a plus. Highly recommended. YMMV.
At 10W/ch all you will ever need is to keep your cables as short and as newtral as possible. You can go as low as 20AWG for the speaker cable since the current isn't high.
Hello Henry, try contacting Luis at Stage3 Concepts, he would be able to suggest and/or build you the best cables for your system.

Good luck,