If a VM guest server2003 crash's can I just isntall windows on another host and point to the old SAN drives and set the old ip would that work?
Probably not without a bunch of work. You need to ensure that you don't jump from Intel to AMD or vice-versa. You will probably need to install a bunch of hardware drivers. You will likely have issues with networking and need to delete the VM based drivers out of device manager. (don't forget to turn on hidden devices if that turns out to be an issue for you.)
It can be done but it isn't pleasant. Consider that any host you are trying to use might be better off being set up as a new virtual host instead!
one more caveat, it is really ugly to "downshift" from multiple processors down to just one. There is a multi-stage process involved. Just don't do it!
It seems like it would be a lot easier to have a backup strategy for your VM guests rather than planning on deploying a physical server to replace a failed VM. Making clones of your VM guests (or even just making backups with a "traditional" backup program like NTBackup or Backup Exec) would make recovery a lot easier than attempting to deploy a physical server in place of the guest, since you'd have the guest's operating system (with whatever service packs, patches, optional components, etc, were installed) and registry instead of a "blank slate" that you'd have to rebuild.