I can’t say what would be best for you, but I got mine Monday, and played it stock for a while. It’s a bit too responsive, so I took a very small O-Ring to space the gap. I can’t tell you the exact size since I just grabbed the one that looked right.
Here it is flush
Sorry it’s a little blurry, my camera wouldn’t focus right. 
Anyway, I plan to switch to Silicon, but haven’t decided whether to go flowable, or buy the rings. I’ve been debating a KK as well, but haven’t made up my mind. You could get it and decide you like to play it stock, but I’m used to something less responsive.