Supported PA sip speakers

Hello there, I have an opportunity to buy 4 Grandstream GSC3506 SIP, seeing as I can’t get paging working on some of the phones in our stores (oh boy how I’ve tried), Yealink if provisioned through RC work, if RC can’t provision them for me, Paging doesn't work or i’m missing something. As for the remaining phones, Grandstream GXP2160, I figured paging is a lost cause on these as they are old and there is ZERO provisioning from RC for them.

Unless someone can give me some insight on where to start with the paging setting up the un-provisioned phones

Anyways are these speakers compatible with RingCentral? I looked high and low and cannot find an answer. 

Thanks a million for the help :)