Oh this is cuter than the other outfits you have listed. My daughter's twins are just now outgrowing 9m, but this might fit. They are like 6m in the waist. The shirts are working buttons down the front?
The shirt is regular working buttons down the front ( not snaps). The pants have elastic waistbands in them. I held these up to my daughter who is 5 months and it is way to big for her.
The only other boy clothing I have is another set of these outfits 3-6 months to list.