287 is good. From Orlando we go I-10 to Louisiana border then I-12 North of the lake. I think it is I-49 through Alexandria to Shreveport; I-20 to just East of Dallas then up through Denton to 287 and pick up I-40.
You can break up the nothing-to-see with a Salt Mining Museum at Grand Saline in East Texas; an Oil Well Museum in (I think) Kilgore; or a side trip through the Palo Duro Canyon (really worth seeing) just South of I-40.
//On edit: I-20 through Mississippi and East Louisiana is some of the worst maintained interstate in the country. The back roads in Canyonlands NP are better.//