If you are going to OC, get the i5, as it has an unlocked multiplier. If not OC'ing, the i7 will win, hands down. However if you can , get an unlocked i7 4790K. (maybe a bigger PSU too)
If you're buying all of these at once, then I'd suggest getting the i5 4690k, the 280x, and an xfx 550w. Or, if you want more headroom, an xfx 650w. If there's money saved, you could pocket it, or you could put it to other parts.