Buy The GTX 750 ti or fork it out on a GTX 970?

Solution
If you want to max out your games go with the 970. If you want to play your games at high to ultra settings, you have several choices which are cheaper (in order of ascending performance): GTX 750ti, R7 265, R9 270, R9 270x, R9 280, GTX 760.

The i3 will slightly hold back the 970's potential but your games will still be very playable.

Here's a benchmark of Watchdogs using a GTX 780 and comparing a Pentium, i3, and i5 paired with a GTX 780.

https://www.youtube.com/watch?v=MbXZF7yUhgc
If you aren't sure whether you need the GTX 750 Ti or a GTX 970, then you haven't really decided on what your gaming expectations are yet. What's your gaming resolution, what settings do you intend to use, and what framerates do you expect to get?

I wouldn't get too hung up over "CPU bottlenecks." Your i3 isn't going to be any faster with a shitty video card than it will be paired to a fast one. Most games will not be drastically performance-limited by a Haswell Core i3, at least not to the point where a 970 has no benefits over a 750 Ti.
 

See over the past 4 years i had the worst pc i could only play games at the lowest settings at nightmare resolutions . So i just want to be able to game at framerates that don't lag and graphics that are not so much but still a little stunning
but i want something that is future proof too that's all
 
If you want to max out your games go with the 970. If you want to play your games at high to ultra settings, you have several choices which are cheaper (in order of ascending performance): GTX 750ti, R7 265, R9 270, R9 270x, R9 280, GTX 760.

The i3 will slightly hold back the 970's potential but your games will still be very playable.

Here's a benchmark of Watchdogs using a GTX 780 and comparing a Pentium, i3, and i5 paired with a GTX 780.

https://www.youtube.com/watch?v=MbXZF7yUhgc
 
Solution
Good info there by razerz, just my 2 cents:

If you wish to fork it out on 970, then you should really opt to go with i5, and I'm not concerned about the slight or considerable bottlenecks here.

The main reason is you mentioned the word future proof, which at one point is not possible as we can't see the future. But going by the trend that games are slowly but steadily evolving to be more and more multi core optimised, an i5 should last you longer than i3.