In my opinion, you're thinking into it too much. The outfit you mentioned, Red Sky seems pretty ideal for what you want, I would just go for it. I'm a CFI and in my opinion, there are many things in flying that honestly just don't matter. There also a lot of things that matter more than you can imagine. Continuing education is key so after your PPL, seek out different ratings, endorsements, locations, instructors, teaching styles, etc. Fly with an instructor that says "That contactlfying guy on BCP is the biggest nut on earth" and then go fly with one who says "Contactflying is God, and God is dynamic proactive rudder". Variety is worth more than any single detail in my opinion. Try to be well rounded and accept constructive criticism from all sources you can find, absorb it and form your own thoughts on the art of dragging tail and inducing drag.