Swap Seagate - Barracuda 2TB to Seagate ST2000DX002. I don't think you will be cramming all your games into that 500MB SSD and this is where SSHD comes in handy, as it accelerates stuff you access frequently, it's not SSD, but it's better than standard mechanical drive.
If you have money to burn, add dedicated soundcard with amplifier (or just external amplifier) and toss in Sennheiser HD8 (or HD 650 if you don't mind your neighbors knocking your walls down)+ some mic - it is a whole other level of sound quality right there compared to all the "gaming" crap headsets being thrown around. That will be 300 bucks extra or so in total, but it is whole other experience.
As for mic, really anything tabletop will do, unless you are some sort e-personality or a damn singer. I, personally, got Razer Siren and I kinda regret it but in an amusing way, this shit is so sensitive that it picks everything that is happening within a frikkin' 2 blocks radius even when I bring sensitivity down to almost minimal. I'd advise something less aggressive there.
Anyway, headset-wise, I was buying pricey "gaming" headsets for years and trust me, when it comes to sound quality they are utter shit compared to some more serious stuff from company which is all about sound and not your usual one stop shop peripherals maker which is all about taking cheap hardware adding lights and "gaming" sticker to it and asking 3 times the price it is worth. I am not even talking that Sennheiser HD8 are utterly indestructible with metal build, detachable cable and replaceable earpads, they even give you spares of each in the box. To compare I had "gaming" headphones from Roccat, Logitech and Razer and all of them without exception broke or started making troubles after a year at most. Roccat was the worst and Razer the "best". These Sennheiser HD8 are two years old and literally 0 issues so far, by my standards that's insane.