ANTOS Mambo - Joomla 1.5 upgrade

I need two websites (that have different content, but identical in structure and identical coponents) updated from Mambo 4.5.2 to Joomla 1.5. Mamblefish is installed on both sites, so the update also must include updating from Mamblefish to Joomfish. As in the original sites, all work must be srictly kept to codepage UTF-8. A few components of the original site (e.g. Simpleboard) do not need to be copied, so component compatibility should not be an issue. I do not know if any template updating would be necessary, but I have updated another site identical in strucure from Mambo 4.5.2 to Joomla 1.1 myself, and everything worked easily with no template modification.