I'm not the most experience person here, but I have a few thoughts. I think that you may find that you *yourself* aren't suited for poly, but that you would be a good partner for someone who is poly. Some poly people look for partners that aren't meant to be their "everything," which is rare in the monogamous world.
For example, if I am already married, but I want an additional partner, the emotional load on the second partner could be less than it is on my spouse. Poly people tend to adjust based on the situation, rather than try to fit a relationship into a pre-defined mold. The level of affection and connection that they feel to someone, and how much that person feels for them, will determine how involved they are with that person.
This doesn't mean that you aren't suited for poly, but I would consider just dating someone who is poly and seeing how that goes. If you don't have a need for "more" when you are in that situation then you don't need to go seeking more.