Forgive me but I didnt take the time read everyones post.
For you I would recommend both Kung fu and Taekwondo, I am a student/instructor of TKD, HKD and Kung Fu...and by you training in either of these styles would expand your ways to far for you to see know.
Your Aikido keeps the combat mind ready, body manipulation etc... TKD will Breed if the right TKD school your foundation in basics, from stances, blocks, Forms and many many kicks, I would almost say since your Trained in Aikido to find a Shito, Ishun,Ryu Karate School to keep your Japanese style and teachings as your core arts.
My Karate master of Iaido Kabudo, told me once you should have your core arts, TKD or Karate, then also have Aikido or Hapkido wich makes you pretty well rounded.
My Grandmaster also said that a person that has only trained in TKD could never beat a person trained in TKD & HKD. The same would go for Karate would never beat a Karate and Aikidoist either or KArate Hapkido, ot TKD Aikido.
But I find training in Kung Fu puts it all together as well. Find a Kung fu School to complete your circle.
I would Highley recommend a Kuntoa, Silat, wich is a killer arts in them selves.
Kuntao is an old kung fu also known as the Punishing art, It will give you lighting fast hands simular to WingChun.
Silat will you give the perception and theories of taking a persons pyrimid , climbing bodies turning twisting and crushing type theories.
TKD,HKD,AKD, Karate, and almost any Kung Fu are a good mix for person to train in. Creating a well rounded warrior.
Study all you can, boxing, kickboxing and more...
The best well rounded Art i have found, I would have to say would be the Hawrangdo, They have every thing from hapkido, kung fu, boxing, kickboxing, TKD, forms, & basics .