We do network installs at work with solaris machines, a simple "boot net - install" and we have a working sun box in 1 hr with latest patch cluster. It is simple to setup the jumpstart server. We have solaris 8 and 9, freebsd, and gentoo images we load on the sparcs. docs.sun.com as a lot of info on setting up a jumpstart server this is of course for sun hardware though.
Buy 1 external CD rom drive, and make sure your servers can boot from USB. Then you can use that to boot/install your OS's for all your servers. And if its a CD/DVD burner, you can use it for backups too