Ask Mr. Smarty Plants

I would like to preface my answer by stating that the mission  of the Lady Bird Johnson Wildflower Center is to increase the sustainable use and conservation of native wildflowers, plants and landscapes.

In the case of nut trees, we have pecans Carya illinoinensis (Pecan), walnuts  Juglans nigra (Black walnut) , hickory nuts Carya ovata (Shagbark hickory), and lots of oak trees that produce acorns for the critters eg.Quercus macrocarpa (Bur oak). Human consumption is limited mostly to pecans..

The term fruit trees usually conjures up the image of apples, pears, peaches, oranges  etc.,  most of which are not native to Texas or the US. Some fruit bearing trees suitable for wildlife include the Hollies [ Ilex vomitoria (Yaupon),Ilex decidua (Possumhaw)], Wax myrtle Morella cerifera (Wax myrtle), and wild plums Prunus caroliniana (Cherry laurel) & Prunus umbellata (Hog plum).  For other possibilities, go to our Native Plant Database and scroll down to the Recommended Species box. Clicking on the map will give you an enlarged version where you can click on East Texas. This will give you a list of 133 commercially available native species suitable for landscapes in East Texas. Clicking on the name of each plant will bring up its NPIN page which gives the characteristics of the plant, its growth requirements, and pictures. Going to the narrow your seach box will allow you to shorten your list. Select Texas under state, Tree underGeneral Appearance, and Perennial under Lifespan. Check sun for Light Requirement and Moist for Soil Moisture. Click the "Narrow your search" box and your list is reduced to 13 species. This will help you select plants that are suitable for your location.

Your question about the best crops for the area makes me wonder if you  might be more interested in farming that gardening. To that end, I recommend that you get in contact with the folks at the San Agustine County Office of Texas AgriLife Extension.