Court recently posted a review on a Dillenger front drive wheel kit. The video includes all the details. It's fairly simple to install. Lots of questions to ask like price range. Do you love the bike or just want something at a low price.
High performance kits show up on EM3ev's website. He's in Hong Kong. Many kits are not low priced. Leed is pretty low power and uses an on-off throttle, I think. That's not ideal. The tech zips along pretty fast.