check out double run of SVS. I did that pre-Fidelium, works great.
I’m using 4- conductor 12 gauge OFC Monoprice on a very good transparent tube system, and it sounds natural, neutral and clear with good microdynamics and musicality. I’ve had Cardas, Kimber, Belden, Monster, and others. It’s very good wire. Spending more doesn’t mean better sound. Highly recommended for bi-amping/bi-wiring.
Gill…if you’re handy, build your own using Canare 4S11 with the best possible connectors you can get within your budget (i.e Furutech 201G or 201R). Very easy to do.
Check out VH Audio for the Furutech connectors (add to cart to see your price).
For the $350 total budget I doubt you will get anything better. Satisfies the sonic criteria you mentioned above.