That's not safe, and I mean it in the literal sense. That brand of PSU is a hazard. Avoid that PSU. Also they are deceptive: that PSU is a two rail supply with 21A and 23A which *should* produce 530W, but they've limited it to a combined 450W. All major reputable PSU companies would label that as a 450W PSU, not a 550W PSU. That's a big red flag -- when you see a PSU, look at the +12V rails. Hopefully you see only one rail (eg, +12V @ 60A vs +12V @ 21A, +12V @ 23A). Now take the amperage on +12V and multiply by the voltage (12) -- that's what honest manufacturers would call it. If you see a "Max Combined" which is lower than this, this should scare you. Especially if it's much lower, like 450W when it should sum to 530W. This is an indication that they're using cheap components which can't handle that much power. Likely using more than 18.75A causes instability with that PSU (450W/2 = 225W = +12V @ 18.75A).
I'd go WD Blue over WD Red since the Red is designed for 24/7 operation in a NAS environment and this is clearly an entry-level gaming build. WD Blue is designed for that and should save you a little bit of money.
The CPU, Motherboard, and RAM are all compatible. I'd strongly suggest you go with 8GB memory though. 4GB doesn't cut it today, you will lose performance and with 8GB around $35 I don't see the reason for it. Since you only have 2 slots, I'd go 1x8GB here. You'll lose dual channel ability but you can upgrade to 16GB without tossing out a 2x4GB kit.
Do note that you'll be using a DVI or VGA cable to connect to the monitor from the onboard video ports. Likely you have one of these cables, but with things leaning towards HDMI and DP it's worth making sure you are aware.