I've got the Manfrotto 1314b setup. Very sturdy, 9' cross bar, the stands are air-cushioned and can hold a monolight if needed. My kids (3 and 5) have yanked on the hung backdrop with no issue.

Muslin needs TLC - wrinkles ironed out or a dryer cycle with fabric softener and those nubby little spheres that beat the clothes up, or work in post. Paper doesn't have the wrinkles, but some reviews indicate a roll is too heavy for the Impact stand, and many rolls are 9' (the Manfrotto set holds them fine for width and weight, the Impact has an 8' cross bar).

Good tip on the velvet, Denise - I may try that out!