Aaron, I would go with a LIB SKATE BANANA 156. It's a little shorter than your GNU, so it will be more park friendly. It's also a BANANA, so you can ride powder with it- no problem. It's really the best all-around park / pow slayer out there. Have fun!

i think it would be fine i m the same size i ride a 152 stairmaster is built for that might be a lil harder to ride powder but i mean it s still doable for sure

its all preference basically, i ride an aperture image 150(forum youngblood) from zumiez and im 6'. whatever feels comfortable for you, i usually judge it by where the top of your ribcage starts

If you have the extra cash get the Never Summer Evo. Rocker/Camber tech blows everything out of the water including any Banana you can find... if you already have your all mountain board and want a stick for straight park size it down and get your spins on... just be sure to dull down your edges for those rails. For your dollar Stairmaster is the way to go