Hi Richard,
dotLRN packages usually are made of 3 packages: the application, the portlet and the applet (dotlrn-? ones). A few packages, like dotlrn-syllabus, rely on existing applications (file-storage in the case of the syllabus) so only the applet is provided.
Regarding content delivery standard, you can install both imsld and scorm, they won't conflict but, yes, at the end you'll have to choose one depending on your needs.
Packages for IMS-LD: imsld, imsld-portlet and dotlrn-imsld
Packages for SCORM: lors, lorsm, lorsm-portlet and dotlrn-lorsm
Hope that will help some.