For the front:
Marathon Plus in a 20"x1.75 (47x406) comes with a reflective stripe for viability. I was worried that the tire would be too thin for the rim but everything ended up working great.
The rear tire is a Marathon Plus Tour with Smartguard in a 26"x1.75" (47x559), also with the reflective strip. The tire mounted up a little easier on than the one on the front, and it turns out it is a little knobbier than I thought it was going to be. Would make an amazing tire for a gravel rider or a long distance touring bike on mixed terrain - like a Long Haul Trucker or Co-Motion Pangea.
Wheel weight for tube, tire, rotor, and wheel - 5.6 pounds, will be more of course with the cassette. Not light but again, overkill is better on a cargo bike.
Next up, the handlebar situation. I had to change it up a bit because of cable routing issues, pictures tomorrow!