You have a lot of options due to the tank size and size restriction you want. Green phantoms look great. Are you interested in an algae and wood eating pleco or one that requires a little more care in the diet like a meat eater. I like the meat eating plecos like the vampire pleco, gold nugget, snowball. My favorite plecos are the panaque family though but will grow over a foot like the Watermelon, blue eyed and royal pleco. It’s all based on your preference.