I-10 to beyond Slidell and then (I think) I-59 to Shreveport to pick up 20.
You gotte cross Louisiana some where. and 59 is better than 20.
No reason to come anywhere near Atlanta. The above route is the one I would suggest except that it is I-12 at Slidell then pick up I-10 again at Baton Rouge. I-49 is a relatively new interstate from Layfayette to Shreveport.
From Shreveport West on I-20 but then I would take US 69 near Tyler to go up to Sherman and US 82, West then to near Wichita Fall to pick up US 287 to Amarillo where you will join I-40 and West all the way to Albuquerque.
This way you will not only come nowhere near Atlanta, but you will miss all the Dallas/Fort Worth traffic. We follow this route from East Texas to Colorado or New Mexico.
