I think I may be able to help you out there.
The only control panel like that I've seen is <a href="http://www.resexcellence.com/files/wish_i_were.hqx">Wi sh I Were</a>, which can be found <a href="http://www.resexcellence.com/software.shtml">The ResExcellence Software page</a>.
But the thing is that I don't think it will help you much, as OS X doesn't respond to control panels (and I bet Darwin is the same way). If what you are trying to do is an unsupported installation, you should be able to go up into the apple menu and find an options panel, which will let you click an "Unsupported Installation". Also, if your looking into installing OS X on a 6500/250 machine that doesn't have some kind of G3 upgrade, I would suggest <a href="http://www.mklinux.org">Mklinux</a>, cause there's no way that OS X or Darwin will run on that machine. For further notes on unsupported installation I would suggest
going to Stepwise's <a href="http://www.Stepwise.com/MacOSXServer/Hardware Support/index.html">Unsupported Hardware Area</a>, which was quite helpful to me when I first attempted to install OS X. And, in the event that the installer program hangs, which happened to me when I tried to install OS X, hold down S (which activates single user mode) and check a Unix book to see exactly what is the problem. Hopefully OS X client will support more machines then OS X server.