Best Practice combine or separate similar dialog boxes like note and calendar event

My question is perhaps subjective so apologies in advance but this is a real dilemma I'm having.

I have a web based customer management program that allows users to add information about a customer, including notes, set calendar events (tasks), create contact log entries, and to create always-visible sticky notes.

Now these records are incredibly similar: notes have a title, body, created by, and created on fields. Sticky notes are made by checking off a 'sticky-note' check box. Contact log entries are just notes that document customer communication, for example, 'Called John to promote new v 2.0 release", and tasks are notes with an alarm date, or maybe a start and end date, sutable for plotting on a calendar.

It would be an easy matter to combine all four types into a single dialog with a radio button or toggle button array at top allowing the user to select a Note, Contact, Sticky, or Task. If I did this I could have one 'super' button that opens the dialog, say, "New Note/Task" that would allow the creation of any of the types. Alternately I could have four buttons, "New Note", "New Contact", "New Sticky", "New Task" that would open the dialog with the correct radio pre-selected.

Or I could have four separate dialogs each devoted to it's purpose.

Or some hybrid, like Note, Sticky, and Contact on one and a different dialog for Tasks, then have either one 'super' new-note button and a new-task button.

I can argue an advantage of combining all into one multi-function dialog in that the user could switch between types, if they added a note about a meeting they could later change it to a calendar task or a sticky note by editing the note.

Any thoughts appreciated!