SoulGrant :
so its ok to get r9 290 even if i wont upgrade my rig for a long time?
my rig:
maximus vi hero
i5 4670k
vengeance pro 8gb
ax860
nzxt switch 810
840 evo 120gb
understand i don't know what you're planning. If all you have is a single 1080p monitor, and you don't plan to get more, then that r9-290 is more gpu then you'll ever need in the lifetime of that computer. If you have a 1440p monitor, again, the 290 would be all you could possibly need for the lifetime of that computer.
If you plan to get a 4k monitor, or 3 1440p monitors, you probably will want the 780ti. Not because the 780ti will be perfect in 4k (its not), but because 2 780tis will crush 4k.
so you see i don't have enough information to know if a r9-290 will be enough for you or not. It all comes down to the resolution of your monitor and future plans for monitor purchases.