Just3, it sounds like you two are headed in a good direction but still in the healing process. And that process takes time, but it does seem like you are both making efforts. I am not one for making lists and contracts, so I think if you are both working toward the same thing -- a joyous, fulfilling, mutually supportive and respectful marriage -- and you keep talking and learning from each other, you will be alright.
I suspect he is encouraging you to find a bf out of guilt over his behavior, and he wants you to know he is on your side now. If you find someone else and get invloved in another relationship, that might mean in your husband's eyes that you've forgiven him. Still, just because he is telling you to do it doesn't mean you have to run right out and look for someone. Nobody wants to be a project for you to undertake! Take your time, assess how you feel, keep building your foundation (you could do a tag search for the word "foundations" for threads here about it), and don't embark upon trying to meet someone else until you feel fully able to trust hubs and are ready to.