First off there is no CPU named AMD FX 8250. There are FX 8150 and FX 8350. Choose one.
None of them are very good upgrades from your Phenom II X4.
Just buy a CPU Cooler and overclock your current CPU.
And no you won't really be bottlenecked if you're playing with an overclocked Phenom or the FX 8350.
Well pardon me for having a typo error on my touch screen it should have been 8150. Reason I ask was I've sold my old pc to quickly friend and looking to see whats best option bet send 6300 and 8150. I've been informed that both will heavily bottleneck my tahiti 7870. What would be the better of the 2 for gaming