I load 8x10 film holders in a standard Harrison tent (36″L x 27″W x 14″) so I would think the Stearman would be no problem. That being said I have a small closet that I hang a blackout curtain on the inside of the door and have a 2’ square table inside and that’s where I generally load film holders and developing tanks.
My favourite change tent/box is the fuji dark box fdb12. I also have the Harrison change tent and the Calumet change box. But for comfort, ease, robustness, and room inside, the fdb12 is great and second only perhaps to a full size darkroom tent construction.