You will be obliged to grow these as three sided specimen plants as they mature. And some people grow camellia (especially Sasanqua) as espallier.

There is nothing wrong with keeping the back branches removed from plants that you have planted close to a building. I wouldn't say that they are 'intended' to be grown that way, but it is certainly a common practice.

Which nursery sells best cold hardy camelia?
I am looking for eye catching red camelia plants and
I live in city of Philadelphia PA.

Camellia Forest Nursery in Chapel Hill, NC, is one of the best sources of cold-hardy camellias. Dr. Clifford Parks, whose son David runs the nursery, is one of the world's foremost authorities on camellias. He has bred many fine new, cold-tolerant camellia varieties. Point your Web browser to Camellia Forest Nursery. They also publish a printed catalog, which you may want to request. The address is 9701 Carrie Road, Chapel Hill, NC, 27516-7955. Their telephone number is (919) 968-0504.