yeah i would go for 390 everyday over the 970 but to say that the 970 only has 3.5 gb of VRAM is a little bit uninformed. and i don't know where you live but 450 seems a little bit expensive for a 390?(Canada i guess ?)
wouldnt it look better to put the led fans as exhaust?
the 970 has 4gb or vram, its just that 3,5gb runs at normal speed and the remaining of the vram (0,5gb) runs a much lower speed.
id do something along those line,
an i3-6100 should be better in single core performance than the AMD cpu plus you have hyperthreading which make you run pretty much all the current game, you can check review online of the 2 compared cpu the i3 is far better.
you don't need 16gb or ram for most game out there (mostly need 16 for video editing and stuff),
1TB is far enough and you can upgrade easily in the future since it doesn't imply changing a part form you computer
you don't need a cpu cooler, the stock one will do the trick if you don't overclock.
i would also suggest a 120/240 gb ssd to use as main/boot drive, makes windows boot faster and you can install your main games on it to make the loading time faster.
after the small amount of money saved form the ram, the cooler, and the hard drive, i would put more money on the GPU, a r9 390 or a GTX 970 wouldn't be bad but considering you budget you can stick with the 380x, just keep in mind the best price performance is at the range of the 390/970. that said i'm a GPU ***** so go with what you think you need.
heres the part list i would do considering your budget : http://pcpartpicker.com/list/G62FTH
hope what i said can help you!!