For most of my work I use a Libec cinema tripod with a 100mm ball head. The head is easily removable and can be placed in anything that will accept a 100mm half-circle. For low-work I use a high hat mounted on a thick piece of plywood, it has just enough clearance to allow for the underside mounting screw and a small amount of head movement. The support can be straddled for stability, although I've never had to do that when taking stills.
For smaller work I have a Bogen tripod of some kind sans-spreader that can do a pretty good impression of the splits. I cut down the center column head support so that there is just enough to fit into the sticks. Total height is a few inches, plus whatever head gets mounted. This is pretty stable since the legs are spread wide, but it's also less convenient than using a high hat or something more dedicated to the task. Then again, you probably have a tripod laying around you could use, so that's one less expense.