I prefer solid core OCC/OFC over stranded after testing a few brands and set ups.
For some reason it performed better in my small modest system. I've tried Silver Sonic, higher end Audioquest, and lower end Kimber Cables. The best was actually "Anti-Cables" done in true bi-wire.
This will sound ridiculous, but I see one advantage to stiff solid core is that the cables suspend in free air on their own....no need for cable risers!!!
It might be worth simply testing really good solid core for a week or so and see how you like it. It seems a lot of folks who use it, swear and stick with it.