I don't know anything about AR10's, but I bought the PA10 stripped upper/lower combo on a whim. So can somebody please tell me what bcg will work with this upper receiver? It is my understanding this upper is made to be compatible with DPMS part, but it looks like the forward assist is in a different location that the DPMS receivers. So what bcg will work? Where can I find the other parts I need such as the forward assist and dust cover assemblies? Thanks in advance for any help.