I would put the Gigabyte OC in the same category as the MSI card and the XFX Merc above all the others including the Saphire Pulse, it's closer to the Saphire Nitro than the Pulse. I'm more familiar with 7900xtx cards and for that the XFX Merc is the loudest of the high end cards but not by much and it can be brought in line with the others by tweaking the fan profile(I haven't bothered on mine), it should also still be quieter without doing anything than any of the more base level cards. The 7900xt cards seem to be using similar coolers to the xtx versions so the equivalent models should perform similarly. Also if you want quiet make sure that your case has good airflow and while we're on the subject of cases make sure your case can fit the Merc if you look at it because they tend to be longer than many cards.The Gigabyte 7900 XT OC and XFX Speedster Merc310 Ultra/Black 7900 XT are in the same price range, too - so there's a few more choices. However, they're all in the $900 USD price (equivalent). I have only read personal reviews (customers who bought them and posted online - although, I asked a couple of them about their cards). So far, they are happy with them.
I want a quiet card, though - so, whatever is most quiet out of these although I understand the AMD-based/centric cards are usually preferred (i.e. XFX, Sapphire - out of these).
I doubt they'd get in the $800 USD/equivalent in my country, any time soon. 'Would be good, though.
You mentioned a $200 gap which puts it in the same ballpark, that's also the pretax price.