ZoneFlex is the name of the AP models, but BeamFlex is still the name of the adaptive beamforming technology.
It requires no specific support from clients or other AP's. Think of it like cupping your hands and yelling at someone across a room. As far as they're concerned, you are just magically louder to him, and to the guy next to you, it magically is quieter to him. That's the simple explanation of BeamFlex technology -- the AP directs its transmissions in the direction where it thinks the client is, which increases apparent signal strength to the client, but decreases apparent co-channel interference/contention to other nearby AP's.
N and AC Ruckus AP's can work together, but I do not recommend deploying them in the same space, because there's no AP/controller level smarts for load-balancing with channel capacity in mind (e.g. 5 users on the N radio would make the 7343 more loaded than 8 users on the R600), or number of spatial streams in mind. Clients rarely are smart enough either to decide to prefer a slightly weaker AC AP to a closer N AP. By using this combination in close quarters, you'll simply increase the chances of getting clients making suboptimal roaming decisions.