Well, PalmReader does have a free version, but it lacks the autoscroll and dictionary that you seek.
I'm not a fan of autoscroll myself, especially that of µBook but just for you, I'll try it out on my brand new Palm Reader Pro that I just bought a few hours ago.
It does 'skip' slightly when you stop it, but it seems to only be attempting to align the paragraphs with the screen; it does not jump back whole pages or anything.