**** UPDATE ******
I bought faux wood replacement blinds online from a company called Select Blinds, and I'm very pleased with them. The blinds are surface mount with very secure brackets that have a positive latch. The blinds can be ordered in exact widths AND length. No adjusting length like the blinds available locally. I like that you can specify which side you would like for the draw strings to be located, and you can select either draw cord or twist wand to adjust the angle of the slats.
My original blinds have a fabric valance at the top. The head rail on the new blinds was too thick to fit beneath the hardware and fabric of the valances. I remedied this by making a 3/4 inch spacer from wood and mounting the valance on this. I painted the spacers to match the other trim.
Total cost for 5 blinds, from 20 inch to 72 inch, was just over $200.
Cedar Creek Lake, Texas
2019 Keystone Loredo 290SRL
2019 Ram 2500 4x4 Cummins crew cab