Help with older computers wireless please

I am trying to get my first wireless working on some ancient windows 98
computers that have ethernet cards and usb(1.1) in them.

There are several free/open wireless access points near me and I would
like to get something that will allow me to survey what's out there and
allow me to connect more than one computer to it. Ideally, something
that would work in multiple modes and that is not a bear to install,
that has an antenna, preferably removable. I'm thinking, what's it
called, a wireless-ethernet bridge.

Any recommendations? Thanks.