Stereo Part Numbers and Compatibility

[Tnexus]

Hi there, I'm looking into replacing my father's Mazda3 stock stereo that's been dead for a while with a functioning replacement OEM unit for Christmas. It's a 2007 s Touring. Looking online I can find refurbished units for a reasonable price, but I'm getting stuck on figuring out compatibility issues. For instance, this seller is selling a bunch of nearly identical versions with different model numbers. Stuff like BAP566AR0, BR9G66ARX, BR9G66ARX, BAR466AR0 which the seller all states all of those "should" work in 2006-2009 models. Obviously I can figure out if it's a 6 CD changer and if it has MP3 options or not, but I was hoping there's a decrypter sheet out there to break down part numbers. I'd rather not buy one and find out it's the lone guy that's incompatible.