Welcome to the forum.
8 inch dob is a good choice but... I'm wondering if your expectations may be a little high. I know mine were when I first started. You will see the moon in great detail, Saturn's rings, Jupiter's moons and a couple cloud bands, but the planets though bright are still small through the scope. And as for deep sky sky, well we like to call them faint fuzzies.
Could I suggest finding a nearby local astronomy club that has a viewing night to get a feel for what various scopes can do first?