Update: Spoke with the Algo rep: Spec'd out (2) 8186 IP Sip horns, and the 8301 IP multicast adapter ( Due to multi speaker and customer requirement for playing music).
Config: The 8301 will be programmed on 2600 as the sip device, build a calls flow to extension 9999, add the device (8301 adapter) - sends the call paging to the 8301, which then multicasts it to the horns.
Sound right? Chime in if I missed anything.