RedHat uses RPMs so for blackbox, here
is one. For IceWM here
. Some other window managers you might consider are Fluxbox
. You might also want to look at XFce
, which is a full featured Desktop Environment like GNOME and KDE but easier on resources. Here
is a link to a XFce RPM.
To install RPMs, as root in a console, type:
rpm -ivh package_name.rpm