Bernice Beauty Camellia has huge flowers, as big as my hand. It also has large leaves and gets to be quite tall in the landscape. I have link several other camellias that grow to very large in the suggestions below.
Be sure to use a well drained soil medium when planting any Camellia as they prefer fall planting with less watering than you might think. In NC our soil is clay so we prefer to use pine bark soil conditioner when planting Camellia, Rhododendron, Mountain Laurel, and Azalea.