SAPPHIRE Toxic r9 280x or GTX 770 series

AOSPA

Honorable
Nov 3, 2013
15
0
10,520
Hello. Im 14, and I have been working on my first build. My first Build consists of:
AMD FX-8350
Corsair ballistix sport 2x4 gb 1600
Corsair 750m (750 watt psu)
sabertooth 990fx r2.0 motherboard
a low end nvidia gt 610 (for now)

I was waiting for the new r9 series (specifically the 280x) and was almost convinced to get it. Only thing that stopped me was no free games. So a week later nvidia slashed prices for their gtx 700 series and added games. I tried comparing benchmarks and doing a lot of research and can't come make my mind. Budget: try to make it under 400$
I came down to these 4 cards. (Suggest me more/better ones if you can)

SAPPHIRE 100363TXSR Radeon R9 280X 3GB (SAPPHIRE TOXIC):

http://www.newegg.com/Product/Product.aspx?Item=N82E16814202044&Tpk=sapphire%20toxic%20280x

ASUS GTX770-DC2OC-2GD5 GeForce GTX 770 2GB (ASUS DIRECT CU II):

http://www.newegg.com/Product/Product.aspx?Item=N82E16814121770

GIGABYTE GV-N770OC-4GD GeForce GTX 770 4GB 256-bit GDDR5 PCI Express 3.0 HDCP Ready WindForce 3X 450W Video Card:

http://www.newegg.com/Product/Product.aspx?Item=N82E16814125462

EVGA GeForce GTX 770 DUAL SuperClocked 4GB 256-bit GDDR5 PCI Express 3.0 SLI Support Video Card 04G-P4-3774-KR:

http://www.newegg.com/Product/Product.aspx?Item=N82E16814130945

And one question, i have different amounts of ram for each card (2, 3, 4 gb) and I plan to do ultra-high settings on the newer games (Tomb raider, bioshock infinite, bf4, COD, Gta 5, AC 4, etc...) so please reconmend which amount i should get.
Thanks.