Your best bet is to get in touch with your local retailer and discuss what you would need with them, but here are a few pointer to get you started.
The main differences in boards are for the disciplines within the sport.
If you are a technical rider and like doing tricks, you would need a kite board with twin tips.
If you like to ride the waves, you will need a kite surf board, one directional and shaped more like a traditional surfboard.
If you are foiling, then you will need a specific foil board that you are able to attach the foil to.