on the same TV?..because some satellite companies offer channels that others don't. I'm talking about International channels, not American channels like HBO or MTV. We want both sets of channels, so we want to use both satellite providers.

Is this a joke??? I don't think you can do that. And why would you pay 2 satellite companys???

It is possible to do that. You will have to use them one at a time though--you won't be able to combine the guides or anything like that.

You could have them both installed but you would only be able to watch one of the companies channels at a time. You woiuld have to unplug your cable running from your tv to the reciever to switch over from one companies channels to the other.You would not be able to switch back and forth between the two with out switching the cable from the tv to the reciever every time

yes you can have both. Have installed both for a few NFL players. They wanted dish for their tv and direct TV they only received the sunday ticket.
You can have both on multi. TV's.
for each TV you nee a line from DTV to the DTV receiver, A line from dish's dish to the dish reciever. Out from the receivers to an AB switch. AB switch to the TV. Then which ever you want to watch, put the switch into either A or B.

Sure as long as you can switch from one to the other. The feeds are similar!