I would avoid Torchat unless you want to open yourself up to all the attacks that hidden services are vulnerable to that regular Tor users are not. Tor to clearnet encrypts up to the exit node. Tor to hidden service encrypts up to the hidden service. Tor doesn't really use PGP, it doesn't even use only algorithms that are part of the OpenPGP standard. It uses TLS though. Yep pretty much this.