Blackberry Chat & GPS Location

I need to create both the client and server for Blackberry, for a chat. Client: Only two features required. 1) Chat among friends 2) Location GPS Server: basically, chat is going to be developed on push notification api of blackberry. So a java push server will be created. Push Notification API can be used as on this link. [login to view URL] After Applicaiton needs to be send to RIM for approval. Details of Currently Running website: Chat is already functional on a website. Now it needs to be expanded so if one user is on website and the other logs in from black berry, they can chat as well. Website is already operating and users can chat, share photos, comments etc etc. Backend for this website is in php. Pls also note, that website chat is on a php script. we need to integrate the above push server with existing php based backend server of website. Budget is US$ 450 but if someone can do in less, he will be prefered, as i have alot of different platforms and tasks after this... If anything unclear, pls ask. -Mobeen