I do not see any SFDC type field in my Marketo instance where i can set the value to contact or person. But i do see a field called Person Type, is it equivalent of that?
The Company SFDC Type is related to the Account records in SFDC. You should be able to see a "SFDC Type" field which will say "Lead" or "Contact" - if you can't see this i suggest filing a ticket with marketo support so they can dig into your specific marketo instance.
Person Type is a Marketo only field. Perhaps you have hidden the SFDC Type field? This is a standard field that comes with all Marketo instances.