For gaming, the point of having a high refresh rate, ie 144hz instead of 60hz, is so you can take advantage of the higher framerate your computer can handle.
In your case, the 750 Ti will not handle higher than 60fps at 1080p in more demanding games. In fact, in many games it won't even achieve a constant 60fps. So there's no point in getting a high refresh rate monitor, unless you upgrade your videocard so that it can crank out higher framerates. You're lucky in that you have an i5 4460, so all you need is the videocard upgrade, unless your power supply is weak then you'll need a new power supply for the new videocard.