[JDEV] Some quick questions?

[GMonkey]

I am currently working on a project that requires xml messages to be 
pushed from a server to a client and xml messages from the client to the 
server?  The client is a c# .net desktop client, the server is a java 
server.  I had looked at soap but they do not have push functionality! 
I looked JMS but it does not have xml as an option, unless using stream 
text, also c# support is not the best, and is expensive.

I found the Jabber protocol.  The project I am working on is not for 
instant messaging, it will be for message delivery between client and 
server.    Does jabber provide Guaranteed delivery, and if the client is 
down queuing of messages, and mass send upon reconnect?
I noticed the ID tag in the message element, could this allow for unique 
  messages numbering so I can rerequest previous messages, if the 
connection is dropped?

I was wondering if Jabber could be used for this?

Sorry for all the questions but I have been looking around and have not 
found a protocol yet, and would prefer to not have to write my own.