How to make notifications for a chat on an Android application with a PHP application server? -

i designing commercial application needs chat feature. use php / mysql application server. have been doing research , found answers raised new questions.

here different possibilities found seemed interesting implementing upstream , downstream communications:

1. gcm using xmpp persistent connection , upstream notifications since php inherently synchronous, doubt reliable scalable application. found possible solution using modified version of jaxl: http://doublenegative.com/tag/xmpp/
2. gcm http downstream notifications. classic asynctask http connection upstream.
3. implement second application server in language different php (jsp, ruby, django) handling gcm via xmpp.

i not know choose between 3 points because don't know find out first solution not reliable if there few users. in meantime, have deadlines , hinder me use different technology less familiar application server.

thank replies !

samuel