The H77 motherboard will not allow you to overclock your "K" (unlocked processor). If you want the ability to overclock CPU, you need a Z77 mobo.
I am not familiar with that power supply, so suspect it may be poor. If you confirm where you are, and what website, you are using, could advise further. Also, you don't need anything like 850w, unless you are planning to add a 2nd graphics card. Is that the case?
Also, I doubt you will need a sound card. On board sound is pretty good, with most mobos. It's something you could add later, in unlikely event you find you need it.
Subject to neither supporting TWO graphics cards, both PSU and mobo are OK. Unless you plan to spend a lot of money, on speakers, or headphones, and have the "ear" to know the difference, you are unlikely to hear any benefit, from dedicated sound card. Like I said, you can always add one, later, but don't think you will find it necessary.
I would recommend getting some sort of HDD, even if only 500GB, rather than JUST SSD. 120GB of SSD can soon get filled with a lot of rubbish, that you just don't need fast access to, unless you have an external drive, for that, and backing up.
So 600W is enough? My friend told me to pick the processor but I am kind of a noob when it comes to this stuff, does the K at the end mean that the processor is unlocked for overclocking? Is it a simple proccess to up the GHz? Would the 600W in the link be enough then?
Also the motherboard in the link will allow me to overclock or turbo boost my processor?