I'm really not sure about setting it during the rebellion, especially not at the trident. Although it was never written in itself there is a canonised series of events that happened. Also its major plus point is its major downfall. We never met Rhegar. How one person portrays him is likely to be entirely diffferent from somebody else. Its like portraying someone elses character. You have to know the person and the character really well before you can do that, and unfortunately I don't think that either of us could claim an intimate knoledge of GRRM or Rhegar. I really do think that a best option would be to set the game maybe two or three years before GoT. All the hosilities of the noble houses are present as well as the political climate being one that we are familiar with without anyone having to have read the later books. This would be my choice, however i'm willing to have a vote and will play whatever is decided by the story teller type person (LDH).