Yeah, both the Primestar and Starchoice LNBFs (not lnbs) should be standard 11700-12200 (10750 LO) LNBFs, and should work. I'm not familiar with the starchoice hardware, but I've had a couple Primestar dishes, and the LNBFs I had, were not the type that switched polarity via voltage, but instead had 2 coax connections, one for H and one for V, but since you're only looking for one transponder, that shouldn't be a problem, and if you ever want another transponder on the other polarity, you could add a DiseqC or 22khz switch. Then again, there may be other versions of the Primestar lnbf that are more modern than the ones I had. The Primestar lnbf I had wasn't the most sensitive, however. You might be better off just getting a cheap lnbf to replace the original primestar. I have one of the cheap standard lnbfs that
Sadoun sells on my Primestar dish, and it fits fine in the lnbf holder.