I am aware of Beauty Tips but it does not appear as though the project has been touched or supported in a couple years. I've been scouring the web and "XX great JQuery tooltip plugins" lists, but all of them seem to position the bubble a set distance from the target (on whichever side you specify) and have a fixed arrow.
http://www.opentip.org/ has the nicest and most configurable jQuery tooltips I could find. They let you specify those parameters. I use them in my own projects. Go to their main page and mouse over STEMS to see a demo.