157 is absolutely fine at your weight. The Evil Twin just isn't damp at all, that's why you found it unstable. Also, being a beginner you might just lack some control and stability.
Go either with the Whatever or the Goliath. Both are great boards. The Whatever being softer and more forgiving, if you don't mind an extruded base. The Goliath is a bit more of a charging board. Good for jumps and a bit more stable, not exactly a park board (for your boxes though.