In Intellij and Android Studio Gradle is more of first class citizen than in Eclipse. Thus, we have to find a way to manage the Eclipse classpath rather than create a whole lot of extra work.
Thus, first get IVYDE plugin from ASF as it setsup an Ivy Cache container for Eclipse, in other words you can load project libs for project via the ivy.xml file during IDE setup which takes care of code completion, etc.
Gradle build script wise rather than write the whole file again in groovy terms you can make use of this new gradle plugin by Blaine Simpson, gradle-ivyxml-plugin.
The jar is at maven2 repo. Because IVY can handle maven that means it also can handle aar android project library files as well.