Uneven natural curls and the perm

Thanks for the help with my "uneven curl" problem. I received a few opinions that said I should perm my hair to even out the natural curl. I also asked my hair-dresser and she agreed and said that the new perms are more gentle and can be "tailor made" to get the curl that matches my natural ones :) Anyway, I've decided to do this and get a perm at the end of the year (when my hair has grown another 5 or so inches). What I want to know is, if I get a perm then, can I re-perm when my hair gets longer? (I am growing my hair long - about waist length) I don't want the top part looking uneven and the bottom looking great!