he himself does not agree with everything the JW's believe in. I feel that the only way our relationship can work is that if I convert. I am willing to do so, to an extent...but I do not believe everything the witnesses do.
Are you totally aware of what "not agreeing with everything the JW's believe in" means? Ask them what it means. You must be in total agreement or you can be disfellowshipped. This is not one of those religions that allows you to accept as much as YOU want to accept, it's all or nothing. And you can't just JOIN for a family member or potential mate, you can study with JW's because of that person, but you must truly accept EVERYTHING they teach before baptism.