I've been taking a Ultra Hair Plus with MSM (made by Nature's Way) that has 200mg inositol and 100 mg choline. My hair has never been better. I'm a woman and my hair was thinning somewhat due to age and that's why I began to take it. However, my husband saw my good results and he's been taking it too and his hair, which was thinning on top and crown, is starting to thicken also. We thought the improvement was from the biotin. If you google biotin you'll find all sorts of information.
Wrenn, thanks for sharing the info! I hope you keep us posted on your progress. My hair is almost waist length, too -- and that's how I want to keep it!