You are giving them considerable authority so it must be someone you trust. It can be whomever you want, a family member, friend, solicitor or accountant. You can have more than one attorney who can act jointly or each act alone. You can appoint different people as your financial attorney and your welfare attorney. If you only want one person to act as attorney it is a good idea to appoint a substitute attorney to step in if your original attorney is not able to act.