uhh the t-halls are more park specific then the ar6, the ar6 are stiffer to handle the all mt..id say go for the 176, you will have more fun on them in the park
i say it depends where youre going to mount, if you wanna go more towards centre then def do the 181s but if your gonna mount back then you could go with either size. I have 185 arvs and im about your size, and i just skied them. Not too big, trust me.