I got mine from Mouser:
https://www.mouser.com/ProductDetail/Analog-Devices/AD827AQ?qs=/tpEQrCGXCy0eTwVO1turw==
Regarding AQ vs SQ, I've been curious about that too, especially with how much of a price difference there is. According to the data sheet the AQ and SQ should behave the same, with the main difference being the working operating temperature. Mouser also says there is a difference in the minimum voltage, but that isn't reflected in the data sheet. Overall I'd bet they sound the same, but no way to know for sure without trying it.
https://www.mouser.com/ProductDetail/Analog-Devices/AD827AQ?qs=/tpEQrCGXCy0eTwVO1turw==
Regarding AQ vs SQ, I've been curious about that too, especially with how much of a price difference there is. According to the data sheet the AQ and SQ should behave the same, with the main difference being the working operating temperature. Mouser also says there is a difference in the minimum voltage, but that isn't reflected in the data sheet. Overall I'd bet they sound the same, but no way to know for sure without trying it.