Go to Sally's Beauty Supplies and see what they have there. I tried some nice colours there. I've also tried Jerome Russell as well. They keep their colour quite well.
I'd say go with the darkest one possible, I did this lots as a teen and I know it fades lots through washing so deep color will last the longest and not turn orange over time!! /emoticons/[email protected] 2x" width="20" height="20" />