The OP wants a snake with presence, some size, maybe even some girth..... for an arboreal snake that is. I don't think a Rat snake is going to scratch his itch. It wouldn't for me.

If it was me and since I can't afford my Amazon Basin I would be going for a that big Carpet. I never really wanted one but after lucking into the one I have he's certainly made me a fan.

My Carpet, ETB, and GTP are some of my best behaved snakes. The Carpet and ETB have never tagged me. Haven't even tried other than making launches at feeding time... But I don't take that personal. It's not me they want.