Your tank in looking great!
here is a pic of my 55 gallon red eared slider and south American cichlids, I have a jack Dempsey and a couple convicts in it. Fish and turtles get along great (though the turtle tried to eat them at first and then gave up). But she has eaten quite a few smaller slower fish in the past. And she eats any plants right always (even tried to eat the fake ones at first)
I like your basking area it's similar to what I did by cutting the bottom off of a 20ish gallon and putting it on top (maximum swimming room