Sam Chin, head of the family internal martial art of I Liq Chuan, is teaching a two-day workshop in Southern California in January. It would be an excellent opportunity for you to experience IP (and aiki) firsthand. Many of his workshop participants are students of aikido and Daito-ryu. He will give anyone who asks a hands-on opportunity to feel him demonstrate what he is talking about.
I'm still not sure why I can't go and see Dan Harden...