I would advocate some space first. As you have said he still loves her but in his words he loves you more. Clearly for the last year that has not been the case. Its a sentence that he knows you will need to hear.
The problem is that if he does still love her then it is extremely difficult to just repress that feeling. You will be grieving for your shattered relationship but like anyone who is in love and has to end a relationship, he will be grieving too for that relationship. The difference is he just wont be able to show it.
Rushing into Counselling and pretending everything is hunky dory might just repress his feelings and keep them hidden away. They could then re surface at a later date.
Personally if you do want to stay with him and of course that is your choice, I would tell him to move out intially to give you and him some space. I would state that he needs to address his feelings and be sure that he wants to be with you. There is nothing worse than someone saying it is over and then low and behold 6 months later he leaves you.
I think people rush these decisions sometimes more in desparation than anything. He should be encouraged to have individual counselling to address his issues and gain closure on this relationship. Only then should you address the issues you both have with joint counselling.
He has paid a horrendous price already for his actions and that is the complete loss of faith that your daughter will now have in him, probably forever, which could possibly affect her own relationships in the future.
Dont rush into anything.