You will note from this PLANTanswers Web site entitled Outstanding Landscape Plants for Northeast Texas
aggie-horticulture.tamu.edu...
that both the Japanese Camellia (Camellia japonica) and the Sasanqua Camellia (Camellia sasanqua) are listed as being very suited for your location. However, they will do better in partial sun or shade than they will in full sun. This Web site gives a lot of information on the care of camellias:
armchairgardener.com...
Here is part of what it includes: They should be grown in partial shade for best flowering; if shade is too dense, flowering is sparse and plants become tall and leggy with few blossoms on low branches. Full sun is not tolerated by most varieties. Plants should be well mulched using pine straw or other organic materials. Mulch helps to preserve soil moisture, prevents growth of weeds, and adds nutrients to the soil as it decomposes. Young camellias are considered to be shallow rooted plants and benefit from a fertilizer formulated for acid-lovers. Regardless of their age, they will not tolerate "wet feet". The soil in the gardens is slightly acidic sandy clay loam. Because of the rich humus content, little fertilization of mature camellias is needed. Camellias are susceptible to only a few insect and disease pests. Tea scale is commonly seen on the underside of the leaves. Spider mites are found during hot, dry weather, and cause a bronze appearance on the top surface of leaves. Camellia diseases include die back (causing stem cankers and the death of branches), petal blight (affecting the flowers), and occasionally root rot problems. A common occurrence in shade is algal leaf spot; a scruffy substance on the upper surface of the leaves that is unsightly but not harmful to the plant. One of the best defenses against camellia disease is to maintain good air movement around and through the plants. Limbs within 12 to 18 inches of the soil should be removed. Plants should be thinned to open the center, and any crossing branches should also be removed. Pruning cuts should be made to an outward facing bud or branch. Dead limbs can be removed at any time. Other pruning is best done immediately after flowering and before new growth begins.