Gaming Question

[TabletopGamer]

I am working on an Idea for a game of myself and my girlfriend. It would basically be a Solo Campaign with my GMPC as backup for the character and to fit the story.

I was gonna use the Witch Archetype: The Warlock. (http://www.d20pfsrd.com/extras/community-creations/cartmanbeck-s-lab/warlock-witch-archetype)

She is gonna use The Witch. (http://www.d20pfsrd.com/classes/base-classes/witch)

Basically would this be ok to run a almost solo campaign.

The story is basically Witch Twins, I don't have a race yet but I honestly thought of Dvati but rule it as two characters as the original designer made.
The twins traveling the world and exploring and having adventurers.

[John Longarrow]

Just curious, but what kind of questions do you have or what kind of feed back are you looking for?

[TabletopGamer]

Do you lot think this will
1. Word
2 Step on each others feel being virtually the same class

What classes would be better to work off one another in a single class

Or what would do well to give great or maximum flexibility and powerful in a gestalt.