uk – Can I bring NEW PC PARTS (still in their boxes) in my checked luggage?

Hi, I hope you have a lovely day so far.
Thanks in advance for taking the time to read my question.

I am packing a motherboard, graphics card, ram, power supply, chip, fans, SSD, external hard drive that are ALL completely new in their respective packages, packaging them all in my checked luggage. (Also a new PC case, which obviously will still be in its box!)

My biggest question of all is if that allows me to do this. I bought all this as a surprise gift for my husband who lives internationally (unfortunately).

I come from the United Kingdom and fly to South Africa. Do I need to declare all these items?
Will it be easier to unpack and wrap them individually to make it look like I've already used them? Do I need to explain my new products to security here in the UK? Is it easier to leave them in their original packaging?

It is my biggest fear, in case the security is not happy with something and confiscate my components that cost almost £ 2k in total.

Thanks in advance, any response will be appreciated.