Google started Android Studio to give you the latest version of SDKs and tools, and that is why they left Eclipse IDE. You can however, if you still want to, install the ADT for Eclipse; see
ADT Plugin (DEPRECATED) | Android Studio[
^]. The SDK is not a part here, you install the Android SDK separately, and download the latest versions and updates in that SDK Manager — even in Eclipse it is like this, and so is in Android Studio.
However, Android Studio is a recommended product, and you should use it for Android Development.
Download Android Studio and SDK Tools | Android Studio[
^]