Depends on whether you are a novice, and what you most want to see. The two Dobs are fine for deep sky work, but if you are not experienced you may find it difficult to locate such objects. They would not be very good for planets or the moon. The Meade with Autostar is a bit down on aperture but at least should be looking at the right part of the sky. Most new observers spend 90% of their time unsuccessfully searching for objects. If your skys are dark then the smallish aperture might not be a problem. Otherwise "Starmans" suggestion of a 6" newt is good.