Matching putter type to stroke shape isn’t a great fitting strategy. In fact research indicates that how you “release” the putter is much more critical. Bottom line: If the putterface is square to the target line at impact it doesn’t matter what it does during the rest of the stroke. Selecting the correct hosel can make all the difference here.
Companies like Odyssey Ping Scotty Cameron and TaylorMade produce fantastic flatsticks But it’s also true that there are some smaller lesser-known manufacturers who also make some really terrific putters.
However I’d say it’s unlikely that a new iteration of the Mini is coming any time soon. Modern fairway wood designs like TaylorMade’s M3 and M4 for example are so good and so long that former Mini players can simply find the right fit and most likely get the same or even better performance.