New Graphics Card for New PC Gamer

Hello everyone I recently made the switch to pc gaming and have come to the point where its time to buy a graphics card. My question is between two graphics card that I'm considering at the moment, though the selection is not final. Im currently debating between the Asus 7970 DirectCU II or a $300ish Nvidia counter part. 

About my pc; I have a 4670k that I chose due to improved integrated graphics and a 760 watt power supply. I also have an atx board and mid-tower case so the 3-slot design is not an issue because all I plan to add to the pci lanes is a sound card. Even if I do consider Crossfire my motherboard pci lane layout is PCI-e 1x-16x-1x-1x-16x-1x-PCI16x so two gpus and the sound card will still fit, but I likely wont consider it even though its and option.

Im am simply go to be gaming and at resolutions from 1920x1080 and below at the moment , however that said older games I will installing texture packs and heavily modding. I was looking at the AMD card due to the 3GB default as the Nvidia cards are $50-$100 more for 4GB versions. I also planned on buying a lower priced ($300ish) card with the mind set of buying another lower priced card a few generations into the future rather than buying a 780 today. So please consider my situation for the first part of my question.

This pc I plan to keep for about 3 years then giving it to my younger brother/ family as our current family computer is about 5 years old but is very seldom used. However my family members are very technically challenged so I bought a lot of parts with them in mind in the sort of "buy for more than 3 years" mentality. This is where the second part of my question comes in: which cards tend to have good build quality and reliability. I mean manufacture, chipset and things like that. I looked into Asus DirectCU II because of their whole none reference design with the sort of added quality to parts . I looked at other manufactures and read their reviews and most of them tended to be mixed but I not sure if they came from people who got a DOA, had to RMA or they just tend to make worse cards. I feel that these are questions not really answered by reviewers, benchmarks and specifications but rather by experience that comes with time of being an avid pc user, something which at the moment I lack. Also one last thing is whether I should buy soon or wait till AMD release the new cards. 

Thank you to all those that read all of this as I do know this is a rather lengthy gpu recommendation question and for any help and suggestions as they are much appreciated.

i highly recommend waiting a few weeks for new amd stuff

as for long term quallity xfx has lifetime warrentys, so you can't really go wrong with one of their cards