azami88

Thanks, It's way overkill for my setup, although the idea is good and could work

Hi, my Fiio E12 emits some background noise (kind of white noise) if used while being charged by a wall outlet powered charger but is dead silent when charged by a powerbank. thus leading me to think the Fiio is fine as long as the power is clean. 
Is there any way to clean up the power of a wall outlet connected Charger? (tried an anker usb hub and a phone charger with no results) 

You're planning to upgrade to a 180W GPU, so the system will draw ~250-300W. The system will have no problem running on a good 450W PSU. It makes no sense to go for a 750W PSU. 
The RM550x is quieter than the G2, G3 and Focus. Of course, if you want a better recommendation, we would have to know where you actually buy from. 

RMx is probably the best one, though Bequiet has the quietest one with its better fan

I would buy EVGA any day because of amazing customer service. Haven't experienced many issues with any EVGA PSU and I have worked in a PC hardware store for 4 years. 

1. You dont need a 750 watt PSU. 550 is more than enough 
2. The entire Focus lines from Seasonic has issues with OCP. Id skip it.
3. Pick up an rmx 550 or G2 550watt. Or a Bequiet pure power 11 500watt or TXM from Corsair. 

Well it's a potato PSU so tehre's no way of knowing if it will cause any damage to your components, but 525W will be enough for that PC.

If Everything is under warranty go for it. You said you won’t be doing anything intensive so it should be fine. I would make sure it’s plugged into a surge protector though.