As at least Hadoblado mentioned, it's better to start by examining those qualities which you most desire in a partner (or girl), since, absurd as it may seem, there is variation even among INTPs.
Here's my quick list in no particular tall order.
- Open-minded
- Empathetic
- Funny as fuck
- Challenges me and others
- Rational and reasonable
- Independent
- Objective
- Skeptical
- Kind and caring
- More extroverted than me
- Can put ego aside and understands the importance of doing so
So which type does this translate to? Well, any type. I would caution you against trying to select for a(ny) relationship by type rather than by the merits of one's qualities. Our knowledge of another's type is simply a combination of our speculation and the person's speculation, and I would trust most people's judgement of character before their ability to determine a person's Myers-Briggs type (myself included).
With that in mind, it would be interesting to see the results of a poll that asks members to mark which type they believe their partner(s) to be.