100w cpu + 75w gpu + rest of system. you need about 350w or so to be safe.
350W - 175W = 175W for the rest of the system. Really? I doubt any "RoS" uses that many watts. That's insane. I usually put the figure at 50W unless the person is running lots of drives or LEDs. 175W is way to much.
PSU I dont know however can you give me a way to find out through the PC? On the back side of my pc it definetely says 230W
Are you sure it doesn't say 230V? That's the voltage input for Greece. Old/junk PSUs have a small switch so you can select what voltage to use, 115V/230V. It's normally red but I've seen other colors. The voltage info is on a sticker on the side of the PSU. Let me link a random one.
https://www.newegg.com/Product/Product.aspx?Item=N82E16817438092
This is the first PSU on I saw on Newegg.com. If you look at the pictures you should see something like this.
This chart tells you pretty much everything you need to know what they claim the PSU can do. 50C output, minor rails up to 120W, can do nearly the entire 850W on the 12V rail, but combined can still only do 850W. You need to find the chart on your PSU to get the info. Warning! Lower end PSUs either hide the data, or lie about it. That's why we read reviews where they test the output and see how well it works.
Edit: That's a good PSU. Not the greatest, but it will work for your needs just fine. If you can find it in your budget that's a good unit to buy.