HyperBBS should work with any Hayes-compatible modem. It's been tried with a Hayes 1200 and an Apple Personal. There are relatively few assumptions about the modem built into the BBS software, but some are unavoidable.
If it doesn't work with your modem, it is possible to change the way the BBS works. This isn't as easy as running the BBS with a modem it already knows, but it isn't impossible either. Before you try it, though, make absolutely sure that that really is the problem.
HyperBBS should run at 300, 1200, or 2400 baud, but it has not actually been tried much with a 2400 baud modem.