Bending and sliding are two different things.
For slides, by which I'm assuming you're talking about sliding a note up and down a string with your finger and not a glass or metal "slide", you want to be able to move the note without generating too much of the annoying string noise you can get. For that, using coated strings to lubricate the sliding a little would be good. As a technique, it isn't a technique I use that much.
If you are talking slide in the "slide guitar" sense, you want higher action and reasonably heavy strings, but unlike with electric guitar, you might not need higher than you have already.
For bending, you hit a problem. For volume's sake, you want thicker strings and higher tension. For bending sake, you want thinner strings with lower tension. If you're plugging in an electro-acoustic guitar (piezo bridge or the like) then electricity has fixed that balance issue for you. If not, start developing hand strength and be resigned that you won't get great slinky Buddy Guy bends on an acoustic without the tone sounding weak and the sustain going away.