psyBNC is available from the AUR.
It can be installed two ways:
1 ) With your favorite AUR Download and Management script AUR_User_Guidelines#AUR-DMS_.28downloading_and_management_scripts.29
2 ) Manually by downloading the PKGBUILD from AUR and running
makepkg -c && pacman -U psybnc
Note: You should probably read AUR and familiarize yourself with the AUR system beforehand.
After you have installed psybnc you must run make menuconfig.
cd /usr/bin/psybnc make menuconfig
This will spawn the psybnc configure program which requires ncurses. If you do not have ncurses use make menuconfig-curses. This will create a valid psybnc.conf. To use the default settings just hit exit as soon as it opens.