In reply to Owen W-G:
> Do Republicans really think that maintaining a presidential office is going to be much cheaper than maintaining the royal family?
Yes, much cheaper... but would we need one? That's the first question to answer.
> And if we elected a head of state, who could you see taking the job?
It could be anyone, although as there would need to be conditions over candidature - deposit, a number of signatures, or something or other only serious candidates would stand. Also, apart from assuming one is needed, you are also assuming he or she would be elected by universal franchise, in some countries the president is chosen by indirect election, designation by assembly, other solutions are quite possible.
It would probably need several ukc threads to make the decision.