Are 3D coordinate data from Sloan DSS-III available & easily accessible to non-pros?
SDSS DR12 Catalog Data
looks like a good starting point,
apparently pretty open to those willing and able to figure it out.
Their
SciServer Compute
site hosts Jupyter notebooks to query CasJobs in SQL.

The Large Scale Structure galaxy catalog under
BOSS value added catalogs
may also be relevant.