I don't know much about the ebike kits. However, in any motorized situation you want to get the bike ready to handle having a motor and higher speeds. Brakes, axles/bearings, tires, lighting, ect
. Most can slap a bike/ kit together, but being safe and making sure your ride is not going to break in a month is where you should start. Make sure your roller is setup how you like everything before you put the ebike kit on or any motor kit on for that matter.
Either way best of luck with your project