What I use for a truing stand is a cruiser type bike turned upside down and mount my newly laced wheel in the front fork. Take your time and pay attention, tightening spokes just a bit at a time. I've done a number of wheels this way with good results. Lacing the rim in the first place is daunting the first time you do it and may require some starting over to do it again until you get it right, but there are guides on U tube and a very good tutorial from Atomiczombie. I have not laced an electric hub to a rim, but have laced extra large drum brakes from light motorcycles onto bicycle rims and I would think that would be similar.
Riding around on wheels you have built yourself is a really good feeling of accomplishment and saves a lot of money. I'm glad that Bairdco encouraged me to give it a try some years ago, so I try to pass that encouragement along to others. I'm an old fellow (70) with a traumatic brain injury (lightning survivor), not a mechanic and don't like puzzles. If I can do it, I'll bet you can for sure.
SB