We had both. Potty was easier for them to sit on and it could move where we needed.
I also did training young (elimination communication) and we did the toilet. It does hinder their independence a bit (though that could just be my child), but we didn’t have room, and like another person said, the toilet is the eventual goal anyways. They do have those built in kid-size seats that you can install on your toilet!
Toilet is the end goal so if baby will take to it then go straight for it! Lots of kids fear the toilet or the flush or something, and a potty also helps them feel sturdy. With the toilet attachment you should also get a footstool for them. Although, they might be a bit too little for their feet to reach it right now.