I think the i3 would be the better option since you have the option to upgrade to an i5-4690K, i7-4790K, or a Xeon E3 1230 V3 in the future, also on the Intel build get the R9 280 instead of the GTX 760, the AMD card should be stronger the Nvidia. Also 430W on that Intel is really cutting it close in terms of power, I'd recommend getting at least a 550W for either build.
Definitely grab a R9-280 over a GTX760, the 280 will blow the GTX760 out of the water.
I did some chances to your intel build. MSI R9-280 gaming + i5-4460. Z series chipset board, is basicly overkill, for a non K cpu, But the G45 gaming is a decent board which is on sale aswell. you could also cheapout on the board, if you grab a H87/H97 or B85 chipset board if you like.
I also made an Decent AMD option
Some MMO´s realy hanging on the cpu, so that is something to keep in mind.