The 750ti will be the all-round better performing card, but I would certainly look in to saving up just a little bit more to avoid shelling out for an upgrade later down the line.
What other specs are you looking at? Perhaps we could help you pick the best 'bang for your buck'?
If not, the i3 is still a capable chip, I'm actually a little interested to see how GTA V will handle multi-threaded processors on the PC version, considering Rockstar are also porting it to the two consoles, the i3 vs i5 might make no difference what so ever, or, it could make a huge difference. Something to look in to I guess.
As far as the graphics card go I (am going to get a lot of flack :F) think AMD hits the best price/performance at that level, look in to something like the 270 or 270x, or, try to find their previous 7000 series models before they got rebadged. May or may not be cheaper.
Are you buying a new set of ram or just reusing your old stuff? 6GB seems a bit of a random number for a ram kit, what type is it?
All in all, since you plan on upgrading later down the line, I would suggest spending most of your budget on a few select parts and getting very good ones, rather than spreading it out and buying a so-so build that you have to replace almost everything off down the line. Because of this, even though the 750ti is the greater performer, I may suggest you go with the i5 build, or invest a little bit more and go for a recent i5.