First, I live in NYC, is there a way to watch just Japanese programming on slingbox for my Mac or on tv?
If you want to be able to watch only Japanesse TV, you will need to have a Slingbox located in Japan. If you have someone there, you can send them the unit and after the installation and the setup, you will be able to connect to it from anywhere, just using a computer (PC or Mac).
Second, how do I get actual item if I do decide to buy slingbox?
It's necessary to determine where do you want to install the Slingbox and your needs to watch TV, have a look at this site about the differences between the Slingbox SOLO and the PRO-HD: