What you need to do to get a hardware modem is buy an EXTERNAL 56k V .92 modem. Most of your PCI modems are going to be Win modems, and it's very unlikely you'll find an ISA Modem in any store.
External USR Modems used to run around 70-100 USD. I've seen other brands as low as 30 USD on the net and at Computers shows, though.