Wow, congrats on finding someone to share the pregnancy journey with. There are definitely men out there who will love "someone else's" baby. My Mom was pregnant with me and her husband was a real piece of work and left while she was pregnant. When I was maybe a month or so old, Mom's roommate brought over this guy, they were friends and he came over to hang out. I guess he totally ignored Mom's roommate and Mom and held me and played with me all night- I got the first date
Long story short he wound up marrying my mom and adopting me, but he's been my Dad since early on. So yes, there are definitely guys like that out there.
Will your baby's biological father be involved in any way?? Mine never was and was only too happy to sign away rights when the time came.