> small as possible (the smallest Fedora/RedHat I could get by
> stripping RPMs was still 650MB).
wow, really? my more or less stripped RH4 is 163 RPMs and a footprint of ~350mb and that is with man pages and all the other junk in /usr/share.
> I would like to work without kernel modules
I'm with you there. however, I would suggest building a minimalist kernel with module support and putting all the standard things compiled in and using modules for extraneous stuff like GFS and cluster services. The reason is GFS etc are a moving target and it's a LOT easier to track the steady stream of bugfixes by just deploying new modules than it is to keep recompiling a full kernel.
unless your webfarm is doing something unusual, NFS will be vastly simpler, easier, and probably a lot faster. I think recent Linux NFS is a much less sucky than it used to be.