Other than the possibility of recumbent as already mentioned (you apparently already ride one, so the learning curve should be short, and not too steep), bear in mind that to get the more upright style from a less upright style is mostly a matter of swapping saddle, stem and bars - all of which you might need to do on a used bike anyhow to get the fit right. Mind you, swapping the stem on a Santana is pretty much an exercise in single-source.