seeking route advice for biking in western Texas NOT on US 90

[bobbiedobbs]

Doing a loop cycling tour starting and ending in Del Rio, TX. I will ride the Southern Tier route from Del Rio to Marfa. Seeking advice/experience on eastward routing return options. Tentative route: 

--North to I-10 via Fort Davis
--I-10 to Fort Stockton
-- US 385, Texas 305, US 190 to Iraan
--US 190 to Eldorodo
--US 277 to Del Rio

A bit worried about the 90-mile ride from Sonora to Del Rio, as it looks rather desolate.

Would appreciate any suggestions on the above, and better alternatives (sorry, fixed on the Del Rio loop concept) and on what to expect re elevation gain, amenities (most likely few if any) AFTER US 90 What about the riding conditions on the non-interstate US highways?  For those riding on I-10, have you had problems re flats from blown up tire steel pieces?  Going in late October/early November. Looks like mixed wind direction, decent temps. Finally, does anyone know of any repair options should that be needed - can't find any bike shop or equivalent beyond Del Rio.