In that case, you are one of the few people who profit from these ultra-highend cards. The 290X does not operate on a fixed clock rate, it can vary depending on temperatures during gaming. The bad info is that the clock seems to often only reach 851MHz. The good info is that there is a bios setting ("Uber-Mode") that allows for continued 1000MHz clock rate. This has two consequencies. One, stuff gets loud. Really, really  loud. And not only loud, high frequencies start to dominate the loudness. Not a problem for you, probably, given the cirvumstancies, but maybe a problem for your neighbours, even down the road? Two, it draws a lot of power, roughly 240W., so you need a very good cooling design.

no watercooling? hmm, i don't think i would want to put an r9 290x into a pc without water cooling lol.

The 290X will render 2560x1440 as smooth as a baby's bottom.
Most games support 1440P and if they don't, a massive margin you can make the games support 1440P by editing the .cfg and .ini files for a specific game.

why ? will it GET ROD'd??? D: ???

No, it won't. The R9 290X uses only a few watts more than the GTX 690 and they weren't spontaneously combusting without watercooling, you'll be fine if your case is adequately ventilated (ie at least 2 ~12 cm fans not including your PSU fan). 

I'd second a i7-4770k rather than i5-4670k just for future proofing, with the current consoles games will start to get optimised for 8 cores so it'll benefit you later on.

Console games can't and won't be using 8 cores/threads on the consoles.
Plus an Intel Dual-Core is on par with the 8-core jaguar.
A quad-core 4670K is more than enough for the future, his motherboard will also be able to upgrade from Haswell to Broadwell when it comes available, if the PC is only for gaming, don't waste cash on the CPU that can be spent for an overall larger performance increase by using that money for a better GPU.

Hyper-threading isn't a replacement for real cores anyway, sure you get some performance boost.