I play old flight and racing sims like need for speed. I'm thinking I just want a better card than the one that came in the machine. Not an off the charts. Something in the $50 - 80 range. Low wattage.
The best thing in the pricerange you are asking for at the moment is the 5670 or the 6670 (badge engineering). They both will run on low-end generic power supplies at about 300W. They will also give you great performance as well, you will be able to play pretty much whatever you want.
I would only recommend it if it was safe. Both of the links you have show total system power so they show the other system components, although the first is only testing gpu so you need to take into account peak cpu power. The second link shows the wrong cpu with a 5870 although it's idling since they're using prime. He has the 910 not the 910e.
AMD rates the 5670 at 61w and the 6670 at 66w. 910 is rated at 95w. Plus 50w for other components. These are max peak watts and 2/3 of the psu is about as high as I would say to go.
@Deemo, what do you mean by badge engineering? They are not simply a rebadge like the 5770/6770 if that's what you meant. The 5670 and 6670 are different, look at the specs.