Light Mountain Henna anyone?

Hello all!
I've posted on here several times about getting some advice about a change of hair color. I've been hemming and hawing about this for several months and this summer I've decided I *need* a change. My hair right now is dark brown (lots of red undertones). I've colored it a semi-permanent chocolate brown before and in the beginning it was almost a magenta color (a look I was *not* going for) but in the end it washed out and months later the reddish brown result was abolutely beutiful. That is something that I want to attain again. I don't know if I will have to permanently color my hair a reddish brown (I'd like to, but right now I'm taking baby steps!) but I would like that for the summer and going into the fall.

I've recenlty started looking at some color and stumbled on light mountain henna. It says it's all natual, won't damage it, and conditions the hair on top of it---I found this very appealing. But I'm more interested if anyone's had good experiences w/henna or knows of a good semi-permanent or permanent color for that matter. I've tried taking this issue of w/my stylist but for some reasons their very limited on color and the colors they have I *really* don't want in my hair. And I'm a poor college student who doesn't have the bucks to pay for on expensive colors. What should I do?

P.S. To give you an idea of what I'm looking for, and example of the color that I'd like to be close to is the current lindsey lohan color.