Unless you work for an agency of the Commonwealth or a third party entity who has signed on to use the system, there is no way to get an OpenSky radio that can even monitor the system. And, even if you have a radio, that does not mean you're going to be able to have whatever talkgroups you want in the thing.
Unlike trunking systems we are all more familiar with, you cannot just program a commercial radio with the right talkgroups and frequencies. Every time a radio on the PA STARNet system is turned on, it affiliates with the system. If the radio is not authorized to be on the system, no dice. Some agencies even require individual end user login when you turn on the radio. This allows a user to pick up any radio, turn it on, login, and then have their custom channel profile available on that radio. Some agencies have a standard statewide channel plan.
We're all in the same boat, unfortunately. Sucks, but there's not much we can do about it.