cat head and tail

catht.awk

#!/usr/bin/awk -f

BEGIN {
   line = 0
   split_line_outed = 0;
   arr[1] = "";
}

{
   line = NR
   arr[NR] = $0
}

END {
  for (i = 1; i < line + 1; i++) {
     if (i > n && split_line_outed == 0 && line >= 2 * n + 1) {
         split_line_outed = 1;
         print "============";
     }

     if (i <= n || i >= line - n + 1) {
         print arr[i];
     }
   }
}

find /your_dir -type f -exec cat {} ; | catht -v n=2000 | pbcopy