about basing the lgneth of your board on your height. As a general rule, that's true and it's what a lot of beginners use to figure their board height. Truth is, your board lgneth depends on your weight. At 100 lbs, your perfect size is like a 136 cm, but since you like going fast, up it one or two cm's so it stays stable at high speeds. As far as board with, you don't need a wide. Well I'm assuming. If your foot's a size 11 and up, then you might want to consider it, but under that, forget about it. Most boards that have a waist that's more than 25 cm are considered wide. So under that, you'll be fine. Good luck out there.