I voted for the magazin only.
Reason:
I think you are very motivated now, but motivation usually doesn't stay that long. I've seen so many people (including myself) starting big projects, but there are only a few who actually have the patience and motivation to pull it through. So make one thing first. See if you can make one or two magazines and if you can keep doing it. That already requires a lot dedication. Additionally managing a whole book would be too much.
Or do a book and not the magazine. Just do one thing at a time.
But I figured the successrate for a magazine is higher, because it doesn't have to have so much content. Even if there is only one issue in the end, it will be useful for EZ.