I want my dark golden brown hair back!!!!

Hello all,
Let me just proceed my situation w/the fact that I haven't seen my golden brown hair color since I was a child. I used to have beautiful dark tawny brown hair in the summer time and now since I'm in the mood for experimentation, I want it back. I have several questions about this:

1) In order to get this particular hair color, I need to do a permanent color. Now is this really wise to do? My current hair color now is the darkest brown, same color as black coffee. I figured to get this color I need to go one or 2 shades lighter. Unless they have a semi-permanent that I don't know about, I don't know how else I could get the color. Could going one shade ligher do much damage to one's hair?

2) I'm still really confused on what shades to that will match my undertones. My hair is brown, but the undertones are cool. Also I'm African American w/ both cool and warm tones in the skin, so I'm losts on that. Any help would be appreciated. Thanks!
cass