Make it smaller

I have several old computers running 4 gb hard drives. I have them at my office, and they run Windows 2k. I would like to put Knoppix on them but if I did then I wouldn't have much room for software I want to install. Could the next version of Knoppix have an option to just install KDE and the basic stuff needed for compiling and other common things? Or mabey just packae selection. I don't need 2 office suites, 2 browsers and 10 text editors, I'm fine with one.

check out damn small linux.
it is based on knoppix. then you can use apt-get install to install everything you like to have in adition (like KDE ) but KDE are among the largest in the entire dist together with OO, and Mozilla.
EDIT DSL is only a 47Mb iso /EDIT