Basically, you file the paypal claim and hope they can pull money from the seller and return it to you. If they decline and you file a charge back against Paypal with your CC company, Paypal will close your account with a negative balance and report you to collections.
Basically, if you value your credit, don't do a CC chargeback against paypal if they side with the seller. I'd file a "Significantly not as described" dispute with paypal and immediately escalate it to a claim ASAP. You are in a tough spot, however, since you have to show proof (link to thread etc) of what you bought and Paypal is notoriously anti-gun.