Palit does a 1660 Super single fan GPU. The 1660 Ti is such a minor step above the Super that I would always look at the Super first. If the price difference is <$20, then get the Ti still.
I would only get a 2060 if you can grab one at (or very close to) $300 US. If you are willing to look at used, there are often 2060 OEM models from Dell/HP that are single fan and should fit the MI 6.
Thanks for the info! I did a quick search, the diff is around 24 USD. Not bad.
2060 OEM models? Hmm let me do a search again.