GPU and RAM upgrade

[Cosmin45]

I want to upgrade my PC but i really don`t know what to pick since i have no experience with building a PC. I want a gaming PC and to play The Witcher 3 and other AAA games at a stable 60 FPS. I only care about FPS but i wouldn`t mind nice graphics. My budget for the GPU is ~200 EUR  max 250 ( 220$ and 270$). My curent build is
GPU: MSI Radeon HD7770 1GB GDDR5  http://www.newegg.com/Product/Product.aspx?Item=N82E16814127687

CPU: Intel® Core™ i3-2120   http://ark.intel.com/products/53426/Intel-Core-i3-2120-Processor-3M-Cache-3_30-GHz

RAM:  KingMax 4GB DDR3 1333MHz 1.5V

Motherboard:  GIGABYTE GA-H61MA-D3V http://www.newegg.com/Product/Product.aspx?Item=N82E16813128539

PSU:  Floston FL500 Extra  500W
+3.3V     20 A
+5V     26 A
+12V 1     24 A
-12V     0.8 A
+5Vsb     2.5 A

I was thinking of buying  STRIX-GTX750TI-DC2OC-4GD5 http://www.asus.com/Graphics_Cards/STRIXGTX750TIDC2OC4GD5/specifications/  But i read somewhere that the extra VRAM won`t be used, compared to the 2GB version. 190 EUR 210$

OR

ASUS STRIX-GTX750TIOC2GD5 http://www.newegg.com/Product/Product.aspx?Item=N82E16814121896&cm_re=Asus_Strix_GTX_750ti-_-14-121-896-_-Product170EUR  190$

OR

Asus NVIDIA GeForce GTX750TI OC  http://www.amazon.de/NVIDIA-GeForce-GTX750TI-Grafikkarte-Speicher/dp/B00ICUGOP0/ref=sr_1_2?ie=UTF8&qid=1433260330&sr=8-2&keywords=nvidia+geforce+gtx+750+ti+4gb

 

And i was thinking that an extra 4 GB of RAM (8GB in total) would be enough for gaming, so i chose the G.Skill DIMM 4 GB DDR3-1333 http://www.gskill.com/en/product/f3-10666cl9s-4gbrl

I have absolutly no ideea of what to pick, i'm not that good with computers and there are a lot of choices and i don`t know which GPU is better. Are the parts that i chose even compatible ? Is the outdated CPU going to hold back the PCs performance ?
 

[Stardar1]

if you REALLY want 4GB at a low end card, then go wor the R9 270x 4GB, if you have the cash, a 4GB 960 would do better.

 

That RAM will work but IMHO your whole machine needs a refresh.

[misthosg]

Get a r9 280, if you search you can find them for around 200 USD, idk how much they go for in Europe