When selecting a suspension fork for your 1000 watt electric bike you want to ensure that it is the suggested length to match the framework on which it is running. If you buy an e-bike, the fork which comes with it will be a good match. A fork that's too long for your frame will alter the handling characteristics of the bike and put in more tension to the head tube designed for this.
This can result in additional levitation causing the frame to crack. This may also boost the stand in the elevation of the 1000 watt e-bike, letting you sit comfortably. A fork that's short will decrease the front end, which will effectively raise the angle of the mind and modify the way the bike handles.
Some forks have adjustable travel, which can allow you to dial in the correct height for the frame, but they are more expensive and not really necessary on electrical bikes. Just get a fork the same height as the frame it was designed for. Examine the frame manufacturer's website to learn what size fork they recommend on the specific framework you've got.
The fork may have an air spring or coil spring and will work fine. A sprung fork could be adjusted with a shock pump to modify the air pressure inside the fork. A fork may want to modify the internal coil spring to a heavier one to fit the increased weight of the completed bike.
The forks also arrive with roofs of different diameters (the upper part of the fork that slides inside the reduced ) from about 32 mm to 40 mm. Since the bike will be quite thick after installing all the parts it is best to find a very rigid fork that can deal with a sizable 8-inch rotor.