A USB dongle seems more convenient for me, I don't need a card, internet isn't that fast and it could block the GPU, looks ugly and I could get a better connection if it's on my desk in the open and not on the floor.
Also, I want some nice looking stuff as this is my ultimate PC so far which I can push my budget with and be better off in the long run so I'll keep the RAM, upgrade the cooler later on and install some SP140's with spray painted green rings. Also gonna spray paint the front panel inner edges green. I saw a pic of it somewhere but I lost it.