It depends on what you need, they can both do everything you need and then some. Ant is arguably more flexible, but the price of that flexability is having to script the entire build process yourself, from sratch. There are a lot of custom Ant tasks out there that offer all kinds of functionality that you can integrate into your own scrips. Dependency management can be handled with Ivy, which is very powerful. You don't have the benefit of a uniform build lifecycle across projects, but that is less important in your case.
Maven, on the other hand, offers a host of project archetypes, which are essentially templates that help you get up to speed with new projects quickly. It also offers dependency management out of the box, and defines a standard lifecycle. You can extend the capabilities of Maven with various plugins.
In your case I'd pick Maven.
Build a man a fire, and he'll be warm for a day. Set a man on fire, and he'll be warm for the rest of his life.