Need help with PC build please

[Huginn]

The difference between i5 and i7 is firmware/software. FFXIV does not currently exploit the advantages of the i7.
Please note that there have been several reports of 8+ core processors causing this game to underperform on Windows based PCs (yes, you CAN play this game on Linux and OSX, see the appdb tab on winehq.org) and the reason seems to be the behavior of the OS using only one of the cores if too many exist.
Be aware that DX11 support will be coming for FFXI and that will be like a free upgrade igf you have a DX11 video card when we finally get it.

If you are looking for a motherboard suggestion, might i suggest the ASUS Gryphon X87 or the ASUS Sabertooth X87 (socket 1150). both offer solid construction, high copper content Japanese made capacitors, cool names and great performance on their PCIe slots (some manufacturers give you lower throughputs on different slots.)
a socket 1150 motherboard will allow you to use the Haswell core processors, which in my opinion, are better than the recall ridden poo fest that the ivy bridge and sandy bridge processors were. also, haswell performs better for gaming, as the threading on games is not usually very high, so the Ivy-E does not offer an advantage.
a socket 2011 motherboard will let you spend more money for no better performance

On the AMD side, don't let anyone tell you that AMD chips are awful. I am currently playoing on an ASUS crosshair III motherboard with a Phenom II x4 965 processor and it handles the game WONDERFULLY. Anything you can buy today should beat the pants off what i have.

And for reference, check out this site: passmark.com which will include spubenchmark.net and videocardbenchmark.net
you will find benchmarks for processors, video cards, hard drives, etc. in order to be better informed about what is better that what at certain tasks without having to invest the time and money of testing it yourself.

by the way, an AMD FX-9590 runs like an intel core i7 4820K