...I'm looking at Isshinryu or Aikido
Like I said I touched a little on Aikido. Definitely a graceful art, with more of the philosophical aspect than the SD. Isshinryu is a blend of Okinawan arts, mostly Goju and Shorin, which I'm just starting and I think definitely complements the TSD.
I know that many TSD orgs have added some weapons, but I cant' help but feel that they lose so much by only touching so briefly on those weapons.
This almost deserves a thread of its own. That baton-twirling mess is one of the reasons that a lot of TSD/TKD schools are looked at as McDojang. They bring in a few weapons that they don't have any kind of a curriculum for or any knowledge with, and they make up forms for them or take weapons forms that they've seen elsewhere and blend them. The students learn these and then think that they actually know the weapon.
For instance, the McDojang I started at when I was a kid, Kim's Karate, taught 3 staff forms, a nunchaku form, and a knife form (when I was there at least). They didn't teach anything else about the weapon. There was no explanaition of movement, no basics, no sparring with the weapon, no application, no discussions about how weapons also teach skills for empty hands, and most of the movements were exagerrated. Now, having some Kobujutsu under my belt and a more anayltical approach to the martial arts, I've realized that what they were teaching is really lacking in martial application. So, pretty much, just baton-twirling...
Cross-training means actually delving into another art, not just adding some moves to your current system that you think may work or look cool in a form without having any knowledge of the technique.
Thanks for bringing that up MBuzzy