krazymace your first question, "Can you view two different channels". No, not on the model I bought but iogear does have a model that you can. You will need to search "IOGEAR wireless HDMI two different channels" and you may find it. If I come across it I will post or PM you. Your other question is the inputs to the unit come from the HDMI outputs of your units. ie... Satellite HD receiver, blue ray player, gaming console or other HDMI output.
My model is the GW3DHDKIT.
You may want to search YouTube videos for HDMI wireless switch. That is where I found my model. Great info on various models. Then search the internet for the cheapest price. Amazon and eBay were not the cheapest.
I have a Georgetown XL 378. And I can tell you what all I did to make everything work.
Let me know if you need any more info.
2013 Georgetown XL 378
2008 Honda CR-V