Big Red Dog, first, read the second post from the top (Sticky: Some common questions...by Iceberg).
You could get the c-band FTA programs just by buying a FTA receiver. You'd also need to have a splitter to split the signal coming from the c-band LNB so that you'd have a signal for each reciver (the analog receiver and the FTA receiver). Your analog receiver most likely controls the polarity by means of a servo motor that twists a probe inside the LNB. Your FTA receiver thus could not control polarity. So you would have to "change channels" on your analog receiver in order to scan and register FTA channels of both polarities. This is doable...but it's cumbersome, and I doubt you'd be satisfied with it. Many times, changing channels on the FTA receiver would require you to change the channel on the analog receiver (in order to change the required polarity). It's just too much trouble.
If your big dish's feed horn also has Ku on it, and if you tried to put that dish's Ku signal to your FTA receiver, you'd also run into the same problem that I described above, namely, you'd have to fiddle with the analog receiver in order to change polarity.
You could replace the feedhorn and LNB with one that changes polarity via voltage. That would enable the FTA receiver to control polarity. But it would probably prevent your Uniden from being able to control polarity. (There are a few analog receivers that can control polarity by both methods, but I dont' think the Uniden Supra is one of them.)
You would have to rely on the analog receiver to move your dish from satellite to satellite.
So, the bottom line is....the polarity problem and dish movement problem complicate the reception of c-band FTA .
For a straight forward, easy to operate system, I recommend that the new user start off with a Ku only system. Get a FTA receiver and a Ku dish. Most people think the best channels are on the satellite G10R at 123 degrees west. So, for a stationary system, you'd probably want to point your dish at that satellite. But if you want to receive the channels on the other satellites, you'd need to get yourself a DiSEqC motor to move the dish. All that stuff is sold by Sadoun on the link at the top of this page.
But you have to know a lot of stuff to install a system. By all means, DON'T TRY TO INSTALL IT YOURSELF, unless you like a challenge and you can deal well with frustration.