You have a hundred threads asking about every CPU and GPU on the market...
If its running hot and you have had it a while, take it out and blow all the dust from the fan and heatsink with compressed air. you can also get msi afterburner and adjust a custom fan profile so the fan runs faster. Also, you live in Australia and its summer, dont run it on hot days if you dont have air con in the room. make sure you have adequate cooling in the case, at least a couple of exhaust fans to get the hot air out. If your going to spend any money now, spend it on more ram and more airflow for your case, or a better, cooler case.
While gaming for awhile when you see 80°+ degrees on the GPU touch the top of the case near the PSU, is it hot too? it might be your PSU the source of the heat not the GPU/CPU, in that case you need a new PSU. (i'm having same problem now)
i have a 600w psu
That link don't work for me, but i'm just saying you should check the PSU before blaming the GPU. No matter what PSU you have.
well my psu doent fell hot
waiting for new gen or upgrading now is really up to you. If you can wait, go ahead. If you want/need to upgrade now, go ahead too.
actually i might just change my case because it have poor airflow
would a hd 7850 or hd 7870 be much of upgrade
no. a 7870 might be a slight upgrade, but not enough to make it worth while. a 7950 would be a good upgrade.