Since you have a couple of pituophis already, a pine is going to be much of a departure. How about a blue or taiwan beauty. Beautiful snakes...decent size too. I'll second the tiger rat snake. There are so many nice rat snakes to choose from.
Or, rather than "hot" go "warm". Be the envy of your herp club, and get a vine snake.
1 adult bull snake: "Dozer"; 1.1 juvenile bull snakes: Oscar and Phoebe; 3 baby red-sided garters; 1.1 macklot's pythons