I agree that you should start more or less with what you have. Take a few hikes now, so that you can see what works for you, and what may not meet your expectations.

And you can also be sure that at least some of this gear will wear out over the course of a full AT. Might be better to replace from the start, rather than coddling it for as long as possible. The hike should be about the hike, not about keeping your head above water with your gear.