If you're setting finance and operations up, and if it expected to be a fair sized company, then I'd hold out for at least 30k to 35k package (depends on what other candidates are in the picture. Remuneration does vary significantly depending on nationality.

Your requirements will also depend on whether you envisage having children at school here - it's HUGELY expensive. I'd be happy tp take this offline and give you a more comprehensive picture.