I wouldn't be afraid of a "race" geometry bike. You are going to be "racing" it anyway! The geometry of the bike is not going to make it any more or less comfortable. Your comfort is based on your contact points and how you are fitted on the bike. You can be just as comfortable on a "race" geometry bike as a more relaxed geometry bike. It's just a matter of how you set the bike up. I do RAAM on a "race" geometry bike because it is the most comfortable bike for me and a "race" geometry bike may be the perfect bike for what you want to do. A century or IM isn't a long ride/race. You don't need a comfort bike!