As far as I recall the 2006 P1 does not have the EST option (channel) so you would have to use retro-discs, which unfortunately are not all that awesome when used on the EST system,
The Hero and the Dom are not so far apart when it comes to flex. I'd say the P1 would be a little to much on the stiff side for eider, depends on what you like to ride. Keep in mind that this is a unisex/men's board though, so it might be aimed at a slightly heavier person than you.
For the Hero I'd go with the Molotov EST (women's) or Exile EST, they gives you the full benefits of the EST footed while being flexible. If you want something stiffer the Mission EST or Cartel EST are your choices. It all depends on your preference, riding style and weight. Jibs + moderate speed = soft, big stuff + full speed = stiff.
Good luck and ride hard!