Go with the HIS 4830. With that cooler, you should be able to overclock it pretty significantly, giving it closer to 4850 performance. The 9800GT and the 4830 (default) are on par with the performance, and since the cooler isn't making the price that much more than the 9800GT, just go with the 4830. Obviously, you aren't looking for the top-of-the-line performance, so the 4830 should do nicely.
4830 just because the one you display has a non stock cooler (ati stock coolers tend to just blow air around instead of directing it out) and supports hdmi. 2 slots though and glows 2 things i don't care much for. Really depends what you play because they are about = overall but have some high and low points, but as far as a package the 4830 is just more recent and gives more new stuff.)