Which would give better gaming performance and allow me to play on higher settings and manageable fps? i'm was going for 2x r9 270X but i don't know if that cpu is good enough. also, the i7 and 290x option is a bit heavy on my wallet, but if that's better i'll go with it.
Getting an FX9370 makes zero sense. Just get an 8320 instead with a good cooler and OC it.
Honestly 290x not really worth it, the normal 290 is a lot better deal imo.
I've recently bought an i7 4770k with R9 290 tri-x card. Best decision ever.
Crossfire is almost never better than a single card for the same price. Get the 290x and a 4770k, that will give you great performance. To save money, I would go with a 290 and 4670k, both good components, and they give about the same performance as the 290x and 4770k, because most games do not need the extra cores from the i7, and the 290 is close enough to the 290x that there isn't much of a difference. You can also get an 8320 and overclock it and get the 290 or a 780 with a good cooler.
As the others have said, get a 8320 and OC it...BOOM a 9370 is there. Crossfiring two R9 270X's isn't worth it, as many games will screw up with Crossfire (e.g Skyrim). Get an R9 290 and OC it, and you will get 290X performance. Honestly, the best deal you can get now is a 780 since all the miners are getting the 290 thanks to its great OpenCL Performance.