Most the people I know who can ride a wheelie for over 100ft are 1. very naturally balanced and athletic to begin with, 2. using a the rear break to control rollover, and 3. taken years to practice and get over that "I'm going to roll over feeling". Getting that balance point and having good arm strength are important to finding that body position that keeps you centered. I'm probably at the same point you are for riding a wheelie and am still reliant on the bikes power to initiate and maintain the wheelie. Good riders use body english, can do it sitting or standing and have crashed alot.