Chopin was known for modifying his compositions, even after an official publication was put out. More than that, he published with multiple publishing houses simultaneously. There could have been two or three "official" publications released at the same time, each with their own peculiarities. This is true for many of his works. If you are looking for a singular authoritative copy, you would be hard pressed to find one. IMO, this does well to serve the music, as we point away from the urtext mafia mentality of the score as a central component of the piece, to actually listening and thinking about the music.
The Paderewski edition contains thorough research and valuable information regarding source documents such as manuscripts, student copies, and first editions. If you are interested in this stuff, be sure to check the extensive notes at the back of these volumes.
If you want some sort of "official" word on the street, check out the National Edition of Chopin Works published by PWM. It is also known as the Jan Ekier edition. This is the current scholarly edition of Chopin's music.
As Pianostreet already has the Mikuli edition, this would be a good place to obtain it.