I am using a 650vA toroidal transformer (transformer rating is a good guide to the amount of inrush current you get at startup) and I have a 10A MCB where the mains enters the cabinet. I used a C curve MCB in place of the more usual B curve, which is a bit more tolerant of short-term surges. Never had it blow - unless you have a much larger transformer you probably don't need inrush protection.