You can check compatibility with this little widget (http://www.slingbox.com/docs/IO/4839/DLW.swf)
Here is the comparison between the two Slingboxes:
Now regarding mobile streaming, it is not considered a high definition display. The nice thing about both Slingbox models is that it will adjust its transcoding output resolution based on the client that is connected to it. So, not only does it provide a good quality picture but it also ensures a minimal bandwidth requirement. Which is 150 Kbps or higher for the Slingplayer Mobile.