"ME, ME, ME."
No, I'm not volunteering. I'm just repeating how your post appeared to my eyes.
The answer is easy: go down to the local Unicorn Surplus and pick one up!!
You don't have to list other people's "needs" in order to actually talk about what you can offer to another person.
First of all, quit looking for a person to fill a specific role. Before you've even met her, you've put her in a box and dictated how she will fit into your life.
Next issue: forget about this "without jealousy" thing. Do you also want her to promise never to be sad, angry, or moody? Life happens, people react the way they react. Even the most poly-hearted person will feel jealousy from time to time. You show me someone who says they've never felt jealousy, I'll show you a dirty rotten liar.
Sorry to be so snarky, I just don't like it when people try to put others in boxes.
Now, in actual response to your question... Basically, yes, keep mingling, keep an open mind, be willing to compromise. Remember, it's not all about you and your wife. The other woman will be a PERSON first, and your girlfriend SECOND.
I don't need labels to define me. They're sticky and I hate the glue they leave behind.