Hi Apmutha
SAIL has no specific support for wanpipe/Sangoma. You should install wanpipe (and perhaps Asterisk) according to Sangoma's instructions. The latest SAIL 3.1 releases (-75 onwards) have support for custom trunk types which will allow you to create a Sangoma trunk.
I'll put up the very latest releases for you later this evening (-83). You will also need the latest smesailenv (-18). sail-3.1.0-83 also has some very nice new js code in it.
Kind Regards
S