I suggest you download Build 100, since it's the very basic Full Version and directly update to Build 148. The first three releases mainly focus on heavily extended Actor, Class and Script Features
To lower confusion the new Build 161, coming during November, will be a Full Release again not requiring any previous release.
There're currently many features broken due to moving overall to C++ mechanics and code. But with each new release features will be back working and optmized.
In addition there'll be two new projects joining the SDK partners program making use of the SDK