Well, both VESC and Hobbywing systems will let you turn it down. More power also means more braking. A bigger battery is able provide a bigger resistive load, which is required for stopping power. The regen braking on my Eovan is strong enough to lose traction on some surfaces.

So you’ll prefer overspeccing a little.

I’ve not looked at kits, except the revel kit. Which seems to have disappeared. If you can find one, they’re know to be great.

For a full DIY conversion I’d be finding and vetting each component individually.

Took a look around on what the DIY scene looks like right now.

With an existing board, I might grab a kit for the electronics from flipsky, and look at buildkitboards for their modular battery and enclosure system. Going that route, using VESC based systems, means you’d need to get comfortable with understanding and configuring the electronics using the VESCTool PC program, as well as wiring the various components together.

The other option is buying the relevant parts of a hobbywing-based production board from a brand like backfire, verreal or wowgo, and bolting them onto your board.

There’s the “mellow” kit which looks similar to the revel kit, except it uses hub motors instead of direct-drive. That means you’d be relying on urethane sleeves which are really uncomfortable compared to full wheels, and potentially difficult to source replacements of, as you can’t just use any wheel.