Answers:
We use Hose-a Swervo ("Gold") or Sousa Gold. Agave only. Tried 1800 - may have to pick more up. A splash of Cointreau rounds it out.
Daily's is the preferred mix, though last evening I found some stuff online I might try.
Yesterday I made 'em differently - instead of adding a sheet-load of ice to the blender beforehand I put straight chilled mix and tequila into the jar and blended, then froze...blended, then froze.
Not quite the same as a frozen drink but not watered down, either.
Two glasses apiece was all we wanted. 'DSG's third glass is full; in the refrigerator for later consumption.
I am going to buy one of these in the near future:
It'll blend and freeze at the same time.