Here are a few cards to look at and the first three are a standard two level upgrade from what you have now and the last card would be a better upgrade but a little over your budget amount.
Going with more ram will not give you the same performance upgrade that a video card will. It will make a slight improvement in some gameplay but you already have 4gb and the most that you can actually use with gaming is around 6gb. I have the task manager open while gaming and the ram usage doesn't go much above 5gb even with things open in the background.
If you prefer the HIS brand then you can look at these. The one that you listed is only one level above what you have now so it wouldn't be much of an upgrade , the chart at the top of the post will show you where the cards fall in order of best to worse.
This is for all intents and purposes the same card but $20 cheaper and the only difference I see is that the fan is mounted in the middle so some of the warm air would be going out the back of the card and into the case. At this point you can go with either one and to tell the truth after futher checking I noticed that the feedback was a little better on the IceQ X and it could be a better fit for you since it's a little less expensive.
Power supply-- OK
Ram-- Ok , If you have Windows 64 bit then at some point you could do an upgrade to either 6gb or 8gb , but it can wait just keep it in mind for the next thing to do.
Which card do you have ? In the post title you said a 5760 and now your saying a 5670 ? If you have the 5670 then the leap to the 6870 would be four levels up and you would then see a massive jump in performance and you would still be ok with the other components. If there were a bottleneck with the cpu all you would have to do is overclock it a little and that would take care of it but I don't see that happening since the stock speed is 3.4ghz and it's a quad core and still a very capable cpu , it will have no problems with the 6870.
yeah its a 5670 HIS Ice Queen, 1gb GDDR5 128bit, and thats good to know and yeah i got windows ultimate 64bit, Also when i take this video card out, and go to back to motherboard gpu, all i gotta do is take out the Cmos Battery and put it back in right?
No it's pretty much a standard size card and it usually gives the dimensions of the card under the details tab and on their web site it will give them uder the specifacations tab. 10.24" x 5.59" x 1.65"