Any of the dive shops on Bonaire offering boat dives could take you and your companions to Klein Bonaire, they're easy to find on line. The bigger problem is I doubt any of those shops will guarantee that you'll get two dives, or maybe even just one dive, over at Klein. Dive sites are typically chosen ad hoc, not planned out in advance.
If my understanding is correct dive boats are only going to Klein for morning dives, not afternoon dives, which will limit the boat dive options and perhaps space availability on morning boat dives.
How many are in your free diving party? It may make more sense to charter a private boat for yourselves to take you over to Klein for your dives, though I'm not sure if it can be just any boat (STINAPA permit required?) or you'd specifically need a divemaster with a boat.