Need Advice for Upgrading, 1440p

[Jooeey]

So currently im running;

Intel 3570k i5 4.5ghz overclocked
AMD 7970 Ghz edition
8 Gb Ram
Windows 8 64bit
on 124gb SSD
1 Tb Hard drive
Corsair Builder Series CX 500w Modular '80 Plus Bronze' Power Supply
Asus PCE-N15 300Mbps 802.11B/G/N Wireless PCI-E Network Adapter

i dont know what model my mobo is as in DxDiag and system info it doesnt say but i got it in the Z77 Gamer" Intel Core i5 3570K 3.40GHz @ 4.50GHz DDR3 Ivybridge Overclocked Bundle

So ive very happy with this build but i think its time to upgrade as i recently got a Asus 27" 2560x1440 monitor (changing to a crossover soon)
and it looks great and is perfect for what i do (Graphic Design)
but as i spend most of my free time gaming, things tend to run around 30fps on high depending on the title.
A few things run better like Lol but im a stickler for 60fps.

So i just wondered what my options are? i dont want to spend a ridiculous amount and i also would like a nicer case(currently have Xigmatek Asgard Pro Gaming Case)

 

[Jooeey]

Ah right thanks.
Do you advise to go with the crossfire option ?
ive heard that not all games are compatible and can get very hot but i guess its the cheaper option ?

Also do you have a case you would recommend ?

 

[Jooeey]

ok so i reckon ill go with the R9 290 and i might as well get the 1000w PS for only an extra £20 so i have the option to CF at a later date.