CCA is often labelled as solid too - that's more the solid core vs stranded (for flyleads) I think. There's alot of nonsense going around with cable these days.
@marine1 here you go:
Our solid copper cabling features a full copper core for maximum conductivity and reliable performance. Available in Cat5e and Cat6, these cables ensure stable, high-speed data transmission for homes, offices, and enterprise networks. Ideal for LANs, server rooms, and data centres, solid copper...
scoop.co.za
I'd go with Cat6
And bear in mind it's different outer sheath (usually black) for outdoor UV friendly cable.
Also, if you're in a high thunderstorm area and you're running cable outside, you'll want FTP or STP (shielded cable) with shielded plugs and network switches with shielded sockets (easily confirmed - the socket has steel around it)
Unshielded sockets:
View attachment 1883927
Shielded sockets:
View attachment 1883929
Completely agree that stock sucks in SA. You should be able to easily find Cat 6, 6a and 7. 6a over 7 if you can get it IMO - 7 is very rigid by comparison and 6a supports 10Gbps over 100m. 6 supports 10Gbps over 50m so if your runs are 50m or less, 6 is fine.