It sounds like you already have a good foundation with the #5 and block plane. I would suggest a low-angle block plane if the current version is not already low-angle. Also, maybe a 2nd #5 and some extra blades. You could set the extra blades with camber to take deeper cuts. Instead of fine-tuning the one #5 you already have for the task at hand or purchasing another slightly more “specialized” tool you can have 2 of the one you’re already comfortable. After all, it is the “Jack” of all planes.