You shoudl definitely be riding a 160. As snowolf said, NS boards have a longer effective edge than similarly sized boards from other brands. For instance my Heritage 158 has more effective edge than a Nitro TG 159 that I used to have.
18 Rossignol Sushi . 17 Arbor Terrapin . 17 Lib x Lost Mayhem Short Fat . 17 Capita Spring Break Slush Slasher . 16 Never Summer Swift . 14 TJ Brand Retro Fish
17 Union Ultra . 17 Burton Malavita Wing . 16 Burton Genesis X
16 Flow Talon