Riesentoter (Giant killer) region is one of the Zone 2 (Mid-Atlantic) regions. Check out the
pca.org site and it shows how the country is divided into geographic zones. Each zone is made up of regions (smaller geographic areas) that some refer to as the local club. Shattenbaum is in Zone 1 (Northeast), as you may know.
The path of membership is to pick out the region you want to join. It is not necessary to reside within that area and some have dual memberships in a primary and secondary region.
Riensentoter (Philly area) is one of the larger regions and may have more events than a smaller one. You may want to attend some events in both regions to see how they fit for you.
As for DE's, once a
PCA member you are welcome at any regions. In fact some regions do not even require the car be a Porsche.