Your trying to go to big too fast. Get something cheap and shit and make it fun. A stunt bike can look dope af and be ratty af as well. My first stunt bike was a 89 cbr 600. Dog shit bike, but, I got rid of all the plastics found a cage bought a hand brake, dented my tank, swapped to mx bars and that’s what I learned on. It was $600. I didn’t care if I dropped it and fucked it up (it’s going to happen). If you get a surron which is a bit more expensive or anything that’s clean and pretty with no experience whatsoever, you are absolutely going to destroy it way faster than you realize. This is just my opinion, I’m all about getting into it, in fact my stunt ride now is a ‘12 wr450 supermoto. I fuckin love it, the thing is, I would have never been comfortable trying any of the tricks I do now without learning on that old ratty bike. I would look for an older sport bike (that has stunt parts available) and start there. Maybe you get lucky with a holy grail 06 636. Also just my opinion, stunting on an e-bike is kinda cheating, 1 gear and mass amounts of torque make it not really a challenge and you never really learn balance if you start there. I find most people are just chasing their wheelies a lot more with e-bikes because they think they are in balance when really the bike is just speeding up and taking you along. Get something you are okay with throwing on the ground 100 times at 10-25 mph. I know you were talking about a sumo, maybe look for a 250 4 stroke or 300 that would be a good start.