I looked in the package installer KPackage, and used "find file" (one of the looking glass icons on the left).
For xorgconfig I found the package guidance-backends.
For xwmconfig I could not find a package.
I was wondering why you would need it. I have been using Kubuntu (and Fedore before that, and Redhat before that) and actually, apart from the first few years, I never needed the x-config.
Anyway, apparantly only xorgconfig is available in the distribution.