I think, especially if you’re willing to pay, to hire someone elsewhere, might get you results faster than trying to get a very specific case natively implemented. Obviously all up to you haha but anybody with decent js skills should be able to set this up fairly quickly 
To populate your select field from a cpt, you can use this as example, the first code part here Images in radio / checkboxes - #2 by manc
Just remove the thumb and replace it with the title in the array. I can post an adjusted version here tomorrow if it’s confusing, just lemme know.