The real question is, how much signal leaks off-beam, that you might pick up in your location?
Here is a list of
DishNetwork satellites for you to try to receive.
Most won't have more than a barker channel in the clear.
Getting NASA on 119° is probably not interesting, considering your other dish.
82° and 91° are a circular pay satellite service from Canada (used to be called Bell Express Vu or BEV).
I wouldn't give you a ghost of a chance to detect anything from those birds.
Last time I looked, they didn't have anything in the clear, either.
DirecTV has circular birds on Ku and Ka band, but they use a different format and won't be received by most equipment.
They're fully encrypted.
Don't recall any other service using circular on Ku over North America.
But with your dishes and location, you might look into South American transmissions.
edit:
Oh, one last thought.
The typical circular LNBF has an F/D of around .6 or .7
So, it won't match a prime feed dish very well.
It'll be inefficient, and see only the center portion of the dish.
If your 6' dish is an offset design, that'll be fine.
Else, you would want something like a
QPF-031 LNB plus AF-120 feedhorn...
... or you could use a surplus DishNetwork flange mount circular LNB with the AF-120 from Invacom.
