There are two types of boards: Trick boards and slalom boards. A good trick board needs a lot of rocker (curvature) on the bottom and the rails should be thick. While a good slalom board has a flat bottom and sharp rails. Fins are also good for slalom and cutting but not so good for tricks. Some boards come equiped with retractable fins so they are good for just about anything.
You can use any type of good strong ski rope for kneeboarding that\’s at least 45 feet long. Although, a good slalom rope is better because you can change the length depending on how big you want the wake to be where you are. But I think that the best type of rope to use would be the special kind of braided rope made just for kneeboarding because it\’s braided design lets you twist it all you want and it is also easier to grip while in the wrap position.
The only thing you need to look for in a boat is the wake. The wake of a good boat for kneeboarding should be about 12 inches high with a sharp peak while travelling at about 18 mph.
Here is a small chart of the approximate boat speeds according to the weight of the kneeboarder.