If your ever looking for a KDE application, check kde-apps
. KBear is in the FTP
section, but you'll see there that a new ftp cleint, Kasablanca
is rated pretty high, so you might want to give that a go instead.
Either way, you can follow a link to their hompages to get the source code. It doesn't look like either have FC2 packages (not on their web site anyway). So just download the source code and read the README and INSTALL files. They will tell you what to do. Usually it's just ./configure, make, make install (as root).