Buchanan's Spoke & Rim is a great resource. I have had them build complete motorcycle wheels for me, and I have built my own wheels using parts purchased from this company. Now that I have discovered how easy and fun it is to bo build my own wheels I doubt that I will ever pay someone to do it for me again. You only need a couple of special tools that are easily available online and not too expensive.
Minibike wheels and motorcycle wheels are similar enough that the info translates easily. Bicycle wheels use much smaller parts and require dedicated tools. If you don't want to buy a truing stand, just mount the bare hub in the frame or fork and go from there. You really only need a stable platform to hold the hub in place while you monitor the lateral and radial runout during the build and truing processes.
While the wheels are apart, get busy with the steel or bronze wool and metal polish.
Turn to You Tube for instructional tutorials and you're in business. After viewing many, I have decided that the tutorials produced by Rocky Mountain ATV are the best.
Once you know how to do this, you'll be the most popular guy in your neighborhood.
Buchanan's Spoke & Rim
How To Lace a Motorcycle Wheel | Rocky Mountain ATV/MC
How To True A Motorcycle Wheel | Rocky Mountain ATV/MC