Anyone Have an Equatorial Motorized Camera Mount?

[astrostu]

Probably a long-shot, but ... does anyone have a portable equatorial mount that tracks in RA that is made for (or adaptable to) a camera? The goal is to be able to take it to a dark-sky site and take long exposures of the sky, so I'm looking for a tracking accuracy to an arcsec per minute or better, but I don't know how realistic that is.