This type of personal watercraft typically has the power of a small car, and the speeds that you're looking for are typical of modern EV motors.
The good news is that means the motors from common electric cars (e.g. the Nissan Leaf: the ones available in salvage are rated at 80 kW or 108 hp continuous, from about 3,000 to 9,000 rpm) will work.
The bad news is that to sustain that power more more than momentarily, or if you want more than a few minutes of high-power operation, you're going to need to carry a huge battery.
The good news is that means the motors from common electric cars (e.g. the Nissan Leaf: the ones available in salvage are rated at 80 kW or 108 hp continuous, from about 3,000 to 9,000 rpm) will work.
The bad news is that to sustain that power more more than momentarily, or if you want more than a few minutes of high-power operation, you're going to need to carry a huge battery.