I'm new to reloading and looking to get started. I will primarily be reloading 45GAP and 45ACP, possibly 9mm later on down the road. I really don't think that I will reload rifle ammo. My question is which would the better press be for my needs? I'm leaning toward the SDB since I only plan on loading pistol ammo. I don't know if caliber changes would be cheaper and easier with a 550. Any input would be greatly appreciated.