good haul !
Yes, lot of folks here use the Primestar dishs and LNB for FTA.
There are many discussions on using the existing LNB, replacing it, living with it if it's a bit odd, putting extra LNBs beside it, etc.
What's the diameter of your particular dish (should be some mold markings on the back side)?
That DishNetwork SuperDish has a linear LNB right at the end of the arm.
It's not a big dish for weak FTA, but it'll do for medium usage.
That's assuming you don't mind having a second dish up in the air.
The two LNBs off to one side are circular.
Depending on your interest, one of them could be used for NASA or Angel on 119º...
See our satellite list for more info on what is available, but feel free to ask questions.
The gang here is happy to discuss all aspects of real FTA with you.