i know lungfish has no problem eating snails, but i was never under the impression that they would actively seek out snails to eat (in other words, i was not under the impression that they are good fish to use to control snail population). i really don't know though to be honest. May be i'm just ignorant about this 
in any case, if you want a lungfish in your community, i would definitely stay away from a WAL.
A SAL should work in most cases. But i personally would also make sure there's not a large size difference between the SAL and the bichirs in the long run.
I had a SAL that got along fine with the bichirs for a long time. But after it got big, it bit the pectoral fin of two of my lapradei (~12", and with one of them, it tore it off at the fleshy base of the fin). The last thing it did that made me separate it is the following (See pics). I admit the bichir in this last incident is at most only half the length of the SAL (and so a lot less mass), and this is probably a rare occurrence.
in any case, if you want a lungfish in your community, i would definitely stay away from a WAL.
A SAL should work in most cases. But i personally would also make sure there's not a large size difference between the SAL and the bichirs in the long run.
I had a SAL that got along fine with the bichirs for a long time. But after it got big, it bit the pectoral fin of two of my lapradei (~12", and with one of them, it tore it off at the fleshy base of the fin). The last thing it did that made me separate it is the following (See pics). I admit the bichir in this last incident is at most only half the length of the SAL (and so a lot less mass), and this is probably a rare occurrence.
