[ from the command line]
% cat /proc/cpuinfo
% cat /proc/meminfo
To see how much memory / swap is being used, see the "top" and "free" commands.
As far as brand, the new machines we've been using are Supermicros; 1u, dual Xeon (currently we're using dual 1.8 Ghz procs for the most part). The Xeon dual procs show up as having 4 processors (0-3) when you view /proc/cpuinfo.