Question to ask, as always in these cases, is how much do you want to spend? Another question is: what other parts do you have, beside the CPU and GPU - do you need a motherboard, RAM, case, PSU, fans, storage, etc?
Not really concern about the cost, just want to have the best parts for these CPU and GPU as I already have them, I need a motherboard, a case, psu, ram, storage (ssd or hdd better?), Fan and how many recommended.
Someone better than me can surely advise you on PC case fans, as I tend to just use what I've had lying around for years.
Now there will be plenty of people who will disagree with my choices, and there are certainly plenty of cheaper options that will still be just as acceptable, but I'd argue that you can't go wrong with the above. Your wallet may say otherwise, though
You're welcome - always good to ask these questions, just to get a sense of what's out there (especially since there is so much choice). The 9600K and 2060 Super are fine products, but won't be made massively better by spending huge amounts of the other parts - just make sure you have a good cooler, plenty of fast RAM, and a good SSD.