We have sailed in the 1 bedrooms on the Wonder (no lounge at the time), the Fantasy, and most recently on the Magic (with lounge). I do not think that you can go wrong with any of the ships, it is, rather, what preference you have.
I usually like longer trips, however my DH and I did not like Fantasy compared to the smaller ships of the Magic and the Wonder. We did a Fantasy Caribbean cruise and we felt that the ship was just tooooooooooo crowded. We ended up using the lounge a lot, as a result, as we ate there for breakfast, lunch and snacks

as it was quite peaceful, where as we found Cabanas a bit of a madhouse when dealing with little ones. We really tried to avoid it. Some people love the larger ships as there are so many activity options, we prefer the smaller ships as they feel so much more intimate (and less crowded). DH does not want to go on the Fantasy again because of how busy it was (and it was a low season first week in May cruise). The rest of the ship was so crowded, I felt that the lounge was necessary for an escape, more than an additional amenity.
We personally loved the Magic and the lounge options. The lounge was smaller, but as we found the whole ship was smaller and less people on board, we did not mind going to the main dining areas with the little ones if we needed to. But once again, we really liked the small plate samplings the lounge had and felt that we could easily make a lunch of the samplings, in the serenity of the lounge. It was so relaxing and, for us, worked beautifully! And in relation to the location of the lounge, we were in the very aft and the walk to the lounge was not inconveniencing at all, especially given the yummy treats that we were eating during the cruise

. We utilized the Magic lounge more as it was so easy to pop in and out and grab coffee, snack, wine etc...It was very easy and was enriching.
On the last day of the cruise, the lounge host mentioned that if she had known we would be eating the vast majority of our dinner meals in the room, she could have requested our dining room servers be assigned another party and then they would not have been relying us for their tips (we tipped them fully although we only used them 20%of the time). We did not realize, but she said that we could have just been placed at an empty table when we did want the dining room experience, and just tipped on the times when we were there. We appreciated knowing that for future cruises.
Either way, your cruise will be lovely!