Since you aren't doing any sort of freestyle, you really don't need a twin unless you like to do some light freestyle or ride switch a ton.
The Burton Joystick is probably my favorite board from that brand. However, it's softer than the Custom and is a full rocker rather than a hybrid. It is a directional twin though. Very fun board to mess around on and still handles the steeper runs well. V-rocker is a pretty mellow rocker so it won't feel too loose.
If you want to look at the NS line, try and see if you can demo or get an SL.
Though the Proto CT is a twin, it will work great for your purposes so if you can get a deal on it, don't hesitate to grab it. Keep in mind that it has blunted tips. So the 157 will ride more like a longer board, but will give you the handling characteristics of a 57. Mid-flex, lively underfoot, and very snappy.