Ultra graphics performance for a penny
As this is your requirement I don't think that the graphics card which are recommended until now will statisfy your future self.
I'd like to future proof, also I'd like to buy in the future new monitor, thouh I'm not sure when.
A new monitor sure is a good idea in the near future. My following config aims to provide as much power as possible in my eyes for a reasonable price.
A new Skylake processor to make your build future proof -
Super fast RAM - 16GB because why not? We want to be future proof right?
- Sapphire Radeon R9 390 Nitro + Backplate
Great graphics card in my opinion - really good performance - performance lies between the GTX970 and the GTX980 for around 350 bucks. I know that you wanted to buy a GTX 970 because you wanted to program for CUDA but when you really want the best performance for the best price your choice should be the R9 390. Alternatively you can use the GTX 970 if CUDA is absolutely necessary.
- be quiet! Shadow Wings SW1 Mid-Speed 140mm
Case fan for a good airflow.
Solid CPU FAN - should keep your cpu cool enough from day to day.
- Phanteks Enthoo Pro M
- be quiet! Straight Power 10-CM 500W
- Seagate Desktop HDD 1TB
That makes 1022-€ where I am from so it should be ~1100$.
An i5 4460 would still be enough in most cases but if you want to be futureproof then a Skylake build won't hurt. Positive thing is that you can still enjoy your games in 1920x1080 resolution as modern cards support VSR/DSR.
This technology allows a user to improve visual quality in games and other content by rendering at a very high resolution (up to 4K) and then displaying that content at a lower resolution supported by the available monitor.
What Is Virtual Super Resolution and How Does It Work?.