AMD’s naming scheme is honestly similar to Nvidias. They have X600, X700, etc (the “X” being the generation of card, the second digit being the model).
So for example, the current gen is the 7000 series, with the 7600 being the lowest, and roughly analogous to the 4060, and the 7900 to the 4090. There are also XT versions which is AMD’s version of the Ti line. They have more VRAM, higher clocks, overclocking, etc.
I’d look at the 6700XT, or the one I have which is the 7600XT. Both have similar specs, the 7600XT is more recent with better performance in a couple areas, but the 6700XT is tried and true, and you’ll be more likely to find a good deal on it. The 7600XT only came out a couple months ago and isn’t anywhere near as well established, but IMO it performs excellent at good temps without any tweaks. Both are great for 1080p or 1440p with modern games.