Great feedback, thanks. it turns out that GDS is be installed on a dedicated NW 7.4 Web AS Java stack since as of NW 7.3 the SAP CE (Composite) is full imbedded in NetWeaver. Verified this with OSS, they said the Master Guide was out of date and they would update it.
One other question I had, the install Guide mentions to install the PI J2EE Adapter Engine component on the GDS server. it's a little unclear though as to if this is component is a new NW install in addition to the GDS NW install (in parallel with it), or if in someway it gets deployed on top of the GDS NW.
Note that this is specific to the GDS server. The PI server (separate) has its own J2EE Adapter Engine. The J2EE adapter engine in question here is specific to GDS.
Any feedback appreciated!