Zezale,
To safely accommodate the added length of the EC-14 Teleconverter with the Zuiko 50mm lens, use port extension #5510.54 + #5510.22 Port Body + #5510.35 Flat Port.
Regarding the 14-54mm lens, our port chart calls for the #5510.24 port body + #5510.45 8" dome. The #5510.22 port body is only 1/8" shorter than the #5510.24 port body and will probably work, however we do not have the 14-54mm lens available for verification. If you try the shorter port body #5510.22, I would recommend being careful with installation, not to scratch the inside of the dome when the lens is fully extended. If you add the EC-14 converter, you will also need to add the #5510.54 port extension.
Regards,