Alright, I am 5'10' and i weigh 165lbs. I want to get a ski that can do everything. I'll be using it for groomed trails and riding glades. When I get better I want to be able to use them a little in the park. I have skied many times before and can parallel ski rather well. I am not concerned with what model ski to purchase, but what size is proper for this style of riding. I don't really want you to just say 'x' size as much as I want people to actually explain this and why it is important. Thanks.