Up-close, direct interaction demands rear projection.
Most screen materials de-polarize light, hurting passive stereo.
For front-projected passive stereo, use a silver screen.
For rear-projection, Stewart Filmscreen's "Disney black" material
(unofficial name) is recommended.
Projector Point stocks
it for GeoWalls.
6'x8' screen = ~ $2000.
Other screen materials that may work are Stewart FilmScreen 200 and Da-Lite's Wide-Angle Screen.