Palit seems to be a good brand. At least it has ramsinks, whereas the XFX and Leadtek lack them. And no, HSFs covering the RAM isn't the same thing.
If you're not too sure about Palit, I would not suggest that you spend the extra dough on the Leadtek/XFX 7600GTs. Instead, I recommend to get the XFX 7900GS xXx Edition for 13.7k to 14k from Rashi. It's a bit faster than the 7600GT and overclocks well too (already oc'ed by a bit out of the box). It can reach close to the 7900GT in performance.
You can get a good deal from Sagarmatha on the Palit 7600GT, as Renegade stated.