just watching a system PXE-boot and install itself into a fully operational system is fun. PXE boot and preseeding is not enough however to accomplish this.
By itself, preseeding only installs a basic operating system. Next, you need to configure all sorts of things and services, install additional software, create accounts. etc.
So there is a whole post-install process that you also need to automate. Preseeding by itself, as I understand it, does not seem to be able to do that for you. But you can execute commands at the end of the installation.
First, I'd like to point out that the alternative to Debian preseeding is, in my opinion, FAI or Fully Automated Installation. I want to make clear that this is a product with a long history that may better suit your needs. I do not use FAI because I find it way to complicated. It seems very powerful to me, but I don't understand it.
I understand preseeding and shell scripts. Putting commands that I would otherwise execute manually are now performed by some shell script. And I think every administrator understands shell scripts and will be able to automate installation with almost no effort by just executing a bunch of shell scripts that install various additional components.
I wrote a small installation 'framework' that can be used in conjunction with preseeding to truly fully automate your installation, without the requirement of learning complex stuff like FAI.
Unfortunately, it is not available yet on-line, but as soon as I find the time, a new project will be started and this small installation framework will be available with some example preseed configuration.
In day-to-day operations I use this script to install servers and laptops. Once you see it you will like it.