don’t buy a 6. Mazda6 & “decent power” does not compute. My sister has had a 2.3 M6 for the last year or so… I can outrun it with my wifes 2.4L alero. Nearly outhandle it too.
I test drove a couple of M6 V6’s when getting rid of my trailblazer last month… NOT MUCH better. Still too heavy and unresponsive. Not enough aftermarket support for what You seem to be looking for.
And… Dont but a 1.8 VW.