We've been using Cisco VoIP for about 5 years now (7940s, 60s, and a 70). Most are daisy-chained without any issue. So far I've had two phones that their PC port has failed, but either I just swapped it with on that wasn't using the PC port or threw a small hub at the station.
Overall I think you should concentrate your concerns on other aspects of the conversion other than the ports on the phone.