Syncing calendar and contacts with my iphone

I am looking for a good/preferred method to have my outlook calendar and contacts sync with my iphone, preferably in both directions. In other words adding a contact or event on my iphone will sync to Outlook and vice versa.  I have a gmail imap account and have a pst file but currently using icloud to sync but it is working well (no exchange account involved).  Also I see multiple calendars in outlook, is it possible to just have on main calendar - trying to keep it as simple as possible.  Thanks for any suggestions!