After a long search, I found a petite jumpsuit at Macy's this Spring, though not velvet. Did not even need any hemming. Quality wasn't that great but I enjoyed the trend and wore it a lot to work and for a family reunion event this summer.
Trick for me was finding one with a long enough rise as so many of the petite offerings were too short in the rise. There were a few from Anthro that were really nice and nearly fit but not quite, so I'd give Anthro a try too.
Good luck!