I have the same recommendation as Ultraviolet. We have an older Feedback Sports model similar to the one that she linked. Both my DH and I comfortably use it, with a height difference of 8" between us. I love the tripod design- it's much more stable than a two-legged design.

While I don't consider any workstand to be "carbon safe", some are better than others. I'm of the belief that you shouldn't clamp frame tubes, no matter what they're made of. It's always safer (and potentially less expensive) to clamp the seatpost. I do sometimes clamp my carbon seatpost but, for most light repairs, I'll just hook the saddle nose over the stand.