My vote is on the mini kelly ii.
You can always get the k25 black Epsom down the road. Who knows how long the mini Kelly ii will be in production. I did read somewhere that the mini kelly might get discontinued, but it has yet to be. Grab it while it’s still in production. I doubt this size will still be made in 5-10 years, but then again with Hermès everything is so unpredictable.
Can you tell us what sizes you currently have in your collection? If you already own a 25 then I’d def request the mini Kelly. Also, keep in mind your lifestyle. Like how many others have said, the mini kelly doesn’t fit anything. I have 3, but what are we really carrying in our bags nowadays? Lol