I think that SUN (or BMC) has a software for Solaris hot standy that works thru the network (no clustering is necessary). At this time i cant remember the name (Guardian, sentinel?) --- there is a similar for HP-UX so those names can be for that....

If u cant find the above software try to google "bare metal restore" & solaris. It is that you want. restore a complete system without re-install it.