ISPs? I've tried dialup.world but the connection is not ideal since both my end and theirs are using VoIP ATAs.
Modems and VoIP's have never had a good history of playing well together. You're bes bet if you're wanting to use a regular modem to to just get a POTS line.
-FltCapt Dallas Vinson, SFI
... There will be a rain dance Friday night, weather permitting!
--- Mystic BBS v1.12 A48 (Linux/64)
* Origin: Legends of Yesteryear (21:3/235)