One reason so many people opt for the 17' is likely the bed size, which is why I wanted to point that out. Many newcomers are not aware that a "double" bed is a very loose term in the RV world.
If the smaller bed is not an issue, a Scamp
16 has more headroom than a Casita
16, is a bit lighter, and would likely be easier to find (especially a newer one). Either would be a significant weight
savings- about 2600 pounds for a 16'er vs. 3300 pounds for a Casita
17'er. That's a lot of extra pounds for 9" of bed!
But it sounds to me like the OP will take whatever shows up at the right price and condition. Scamp
... Ford or Chevy...